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Question
In the following diagram showing dispersion of white light by a glass prism, the colours 'P' and 'Q’ respectively are:

Options
Red and Violet
Violet and Red
Red and Blue
Orange and Green
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Solution
Violet and Red
Explanation:
The splitting of white light into its constituent colours is known as light dispersion. The spectrum is the band of seven colours produced by splitting white light. All of the constituent colours of white light have the same velocity in vacuum, but their velocity changes when they pass through a transparent 'medium' like a glass prism. Different colours are diverted by different angles on the prism's initial face. Violet's minimum speed is deviated by the maximum angle, whereas red's maximum speed is distorted by the minimum angle. As a result, the letters 'P' and 'Q' are violet and crimson, respectively.

RELATED QUESTIONS
In the following ray diagram the correctly marked angle are:

(a) ∠i and ∠e
(b) ∠A and ∠D
(c) ∠i, ∠e and ∠D
(d) ∠r, ∠A and ∠D
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
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.
(i) A ray of white light breaks up into its components while passing through a glass prism. Draw a ray diagram to show the path of rays.
(ii) Mark the least deviated colour in your diagram
(iii) Why do different coloured rays deviate differently in a prism?
A beam of white light is shone onto a glass prism. The light cannot be:
(a) deviated
(b) dispersed
(c) focused
(d) refracted
The wavelengths of violet and red light are 4000 Å and 8000 Å respectively. Which of the two has the higher frequency?
The wavelength range of white light is ______.
A wave has wavelength 50Å of State the speed in vacuum.
Say TRUE or FALSE
After passing through a prism, white light splits into a band of seven colours
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?
