Physics
How does the deviation produced by a triangular prism depend on the colour (or wavelength) of light incident on it?
Answer
Speed of light in a transparent medium decreases with the decrease in wavelength of light. Therefore, the refractive index of glass (material of prism) increases with the decrease in wavelength of light.
Hence, the deviation produced by a prism also increases with the decrease in the wavelength of light incident on it.
For example — In visible light, violet colour ( wavelength λ = 4000 Å) is deviated the most and red colour (wavelength λ = 8000 Å) is deviated the least.
Related Questions
For which colour of light is the refractive index of a prism material the minimum and for which it is the maximum?
Name three factors on which the deviation produced by a prism depends and state how does it depend on the factors stated by you.
(a) Write the approximate wavelengths for (i) blue and (ii) red light.
(b) The wavelength of violet and red light are 4000 Å and 8000 Å respectively.
Which of the two has higher frequency?
Write the seven prominent colours present in white light in the order of increasing wavelength.