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Question
Fig. shows a ray of white light that passes through a prism and produces a spectrum.
(a) Name the phenomenon that is taking place.
(b) What colour would you see at X and Y?
(c) What radiation would you detect above X and below Y?

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Solution
(a) Dispersion
(b) Red colour at X and violet colour at Y.
(c) Above X, we would detect infra-red radiation and below Y, ultra-violet radiation.
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