A person has normal vision, but he cannot distinguish between red-green colour. Why?

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(a)

Mention few important features of visual system of a person?

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Draw ray diagram each showing (i)myopic eye and  (ii) hypermetropic eye.

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Why do we see a rainbow in the sky only after rainfall?

2

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Why is the colour of the clear sky blue?

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What is the difference in colours of the Sun observed during sunrise/sunset and noon? Give explanation for each

2

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What is meant by the term 'power of accommodation' of human eye? How does it help a person to see nearby as well as distant object clearly.

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(a) What is the meant by the power of accommodation of an eye?
(b)A person with a myopic eye cannot see object beyond 1.2m directly. What should be the type of the corrective lens used? What would be its power

2

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What is the colour of the clear sky during day time? Give reason for it.

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A star sometimes appears brighter and some other times fainter. What is the effect called? State the reason for this effect

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What is a spectrum? Why do different coloured rays deviate differently on passing through a glass prism?

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Why does the sun appear reddish early in the morning? Will this phenomenon be observed by an observer on the noon? Justify your answer with reason.

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What is meant by scatting of light? The sky appears blue and the Sun appears reddish t sunrise and sunset. Explain these phenomena with reason.

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(a)

What is meant by scattering of light? Use this phenomenon to explain why the clear sky appears blue or the sun appears reddish at sunrise.

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