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प्रश्न
Describe an activity to show that the colours of white light splitted by a glass prism can be recombined to get white light by another identical glass prism. Also, draw a ray diagram to show the recombination of the spectrum of white light.
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उत्तर
The phenomenon of dispersion of white light through a prism and then its recombination can be explained with the help of two identical glass prisms. For this to happen, white light is made to made to fall on the surface of the prism. Since different colours of white light have different wavelengths, the amount of bending of light is different. Red light bends the least and violet light bends the most. So, we obtain a spectrum of seven colours, with violet light at the bottom and red at the top. This spectrum is then made to fall on an indentical prism, which is kept inverted. When the spectrum passes through the prism, all the colours bend once again, resulting in their recombination (as shown in the figure below). Hence, the light coming out of the second prism will be white.
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संबंधित प्रश्न
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Draw the ray diagram showing refraction of light through a glass prism and hence obtain the relation between the refractive index μ of the prism, angle of prism and angle of minimum deviation.
A prism can produce a minimum deviation δ in a light beam. If three such prisms are combined, the minimum deviation that can be produced in this beam is _______________.
By properly combining two prisms made of different materials, it is possible to
(a) have dispersion without average deviation
(b) have deviation without dispersion
(c) have both dispersion and average deviation
(d) have neither dispersion nor average deviation
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A thin prism is made of a material having refractive indices 1.61 and 1.65 for red and violet light. The dispersive power of the material is 0.07. It is found that a beam of yellow light passing through the prism suffers a minimum deviation of 4.0° in favourable conditions. Calculate the angle of the prism.
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A ray of light is incident on a prism whose refractive index is 1.52 at an angle of 40°. If the angle of emergence is 60°, calculate the angle of the prism.
The refractive indices of material for red, violet and yellow colour light are 1.52, 1.62 and 1.59 respectively.
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