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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 figure in which a student has marked the angle of incidence (∠i), angle of refraction (∠r), angle of emergence (∠e), angle of prism (∠A) and the angle of deviation (∠D). The correctly marked angles are
(a) ∠A and ∠i
(b) ∠A, ∠i and ∠r
(c) ∠A, ∠i, ∠e and ∠D
(d) ∠A, ∠i, ∠r and ∠D
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
In the following diagram the correctly marked angles are :
(a) ∠A and ∠e
(b) ∠i, ∠A and ∠D
(c) ∠A ∠r and ∠e
(b) ∠A ∠r and ∠D
In the figure given alongside, a narrow beam of white light is shown to pass through a triangular glass prism. After passing through the prism, it produces a spectrum YX on the screen.
- State the colour seen
- at X, and
- at Y.
- Why do different colours of white light bend through different angles with respect to the incident beam of light?
In the figure given alongside, a narrow beam of white light is shown to pass through a triangular glass prism. After passing through the prism, it produces a spectrum YX on the screen.
Why do different colours of white light bend through different angles with respect to the incident beam of light?
Make two diagrams to explain refraction and dispersion.
What acts as tiny prisms in the formation of a rainbow?
When white light passes through a prism, it ............
A ray of white light falls on a prism. Draw a ray diagram to show that the prism disperses the white light.
What do you understand by the term spectrum? Name the various colours present in the spectrum of sunlight.
Explain the cause of dispersion of white light through a prism.
What do you understand by the term spectrum?
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.
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.
If a monochromatic beam of light undergoes minimum deviation through an equiangular prism, how does the beam pass through the prism, with respect to its base?
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?
Write the range of wavelength of the ultraviolet spectrum.
Observe the given figure and write appropriate phenomenon of light in the box.
Say TRUE or FALSE
Rainbow is formed by dispersion of which light by water drops
When white light enters a glass prism from the air, the angle of deviation is least for ____________.
Name the scientist who was the first to use a glass prism to obtain the spectrum of sunlight.
State the correct sequence (1-7) of colours in the spectrum formed by the prisms A and B, shown in the following figure.
The periscope is an optical device with a polished surface that reflects the light falling on it.
In the following diagram showing dispersion of white light by a glass prism, the colours 'P' and 'Q’ respectively are:
When sunlight passes through water droplets in the atmosphere it gets dispersed into its constituent colours forming a rainbow. A similar phenomenon is observed when white light passes through a prism.
Which colour will show the maximum angle of deviation and which colour will show the minimum angle of deviation?
When sunlight passes through water droplets in the atmosphere it gets dispersed into its constituent colours forming a rainbow. A similar phenomenon is observed when white light passes through a prism.
Instead of sunlight, a green-coloured ray is passed through a glass prism. What will be the colour of the emergent ray?
