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How do the iris and pupil respond to (i)...

How do the iris and pupil respond to (i) dim and (ii) bright light ?

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(i) When the light is dim, the iris expands the pupil to allow more light into the eye.
(ii) When the light is bright, the iris contracts the pupil to llow less light into the eye.
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ZEN PUBLICATION-THE HUMAN EYE AND THE COLOURFUL WORLD-ZEN ADDITIONAL QUESTIONS SECTION - SHORT ANSWER TYPE QUESTIONS - I
  1. Name the parts of the eye which help in this phenomena and state how t...

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  2. Explain the changes taking place in the cilary muscles when we focus o...

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  3. How do the iris and pupil respond to (i) dim and (ii) bright light ?

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  4. Name the screen on which an image is formed in the eye. What is the ra...

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  5. How can change of size of eyeball be one of the reason for (i) myopia ...

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  6. Explain giving reason the type of lens used to correct the defect of v...

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  7. Name the part of eye where the image is formed in a nornaml human eye....

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  8. What is hypermetropia or far-sightedness ? Name the type of lens used ...

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  9. What is presbyopia ? Write two causes of this defect.

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  10. What are bifocal lenses ? Who needs to use them ?

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  11. A person is able to see objects clearly only when these are lying at a...

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  12. What is dispersion ? What happens when light is passed through a glass...

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  13. A beam of white light falling a glass prism split up into seven colour...

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  14. List the three phenomena of light responsible for the formation of rai...

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  15. A beam of light consisting of red, blue, and yellow colours is inciden...

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  16. When a beam of white light is passed through a triangular glass prism,...

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  17. Name the phenomenon responsible for (i) advance of sunrise (ii) colour...

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  18. A star sometimes brighter and at other times fainter. What is this eff...

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  19. Why do we see a rainbow in the ske only after rainfall ?

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  20. Mention any four phenomena that can be observed due to atmospheric ref...

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