Question

2) Read the following paragraph and answer the following questions:
In vacuum, the velocity of light radiation with different wavelength is the same. But in a material medium, the
velocity of different colour radiations is not the same and they travel with different paths. Due to this, the
refractive index of the medium is different for different colours. If white beam of light is incident on a plass
prism, the angle of refractions for different colours is different. When sunlight is incident on the refracting
surface, then it gets splitted into seven coloured spectrum and emerges out. The splitting of light into its components
colours is called dispersion.
Sir Isaac Newton was the first to use a glass prism to obtain the spectrum of sunlight. A glass prism is a
transparent medium bounded by two plane surfaces inclined at an angle. When white light is dispersed into
seven colours by a prism, different colours of light bend through different angles with respect to incident ray. Out
of these seven colours, red light bends the least, while violet light bends the most so, the rays of cach colour
emerge along different paths and become distinct. Hence, we get spectrum of seven different colours.
Questions:
(i) How does emergent rays appear?
(ii) Write the colours of the spectrum
(iii) What is dispersion?
(iv) What is a spectrum?
(v) Which light deviates the least and which one deviates the most?​

Answer 1

Answer:

2) seven coloured

3) When sunlight is incident on the refracting

surface, then it gets splitted into seven coloured spectrum and emerges out. The splitting of light into its components

colours is called dispersion.