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प्रश्न
A prism causes dispersion of white light while a rectangular glass block does not. Explain.
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उत्तर
In a prism, the refraction of light takes place at the two slant surfaces. The dispersion of white light occurs at the first surface of the prism where its constituent colours have deviated through different angles. At the second surface, these split colours suffer the only refraction and they get further separated. But in a rectangular glass block, the refraction of light takes place at the two parallel surfaces. At the first surface, although the white light splits into its constituent colours on refraction, these split colours on suffering refraction at the second surface emerge out in form of a parallel beam, which gives an impression of white light.
संबंधित प्रश्न
Why is the colour red used as a sign of danger?
How does the deviation produced by a triangular prism depend on the colours (or wavelengths) of light incident on it?
In following diagram shows a thin beam of white light from a source S striking on one face of a prism.
What conclusion do you draw from the observation in part (b) above?
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?
(i) Draw a diagram to show the splitting of white light by a prism into its constituent colour.
(ii) Draw another diagram to show how the colours of spectrum of white light can be combined
to give the effect of white light.
Write the approximate wavelengths for blue.
Draw another diagram to show how the colours of spectrum of white light can be combined to give the effect of white light.
What is understood by the term dispersion of light? What is its cause?
Explain, why quartz prism is required for obtaining the spectrum of ultra-violet light?
The wavelengths for the light of red and blue colours are nearly 7·8 × 10-7 m and 4·8 × 10-7 m respectively.
Which colour has greater speed in glass?
