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A person looking at a mesh of crossed wi...

A person looking at a mesh of crossed wires is able to see the vertical wires more distincly than the horizontal wires. Why ? How can it be corrected ?

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This problem is due to astigmatism of the eye. This defect is removed using a cylindrical lens with appropriate axis and suitable radius of curvature.
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PRADEEP-RAY OPTICS-Very Short Answer (d)
  1. A short sighted person may read a book without specs. Comment.

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  2. A hypermetropic person has problem in driving without specs.

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  3. A person looking at a mesh of crossed wires is able to see the vertica...

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  4. What is meant by depth of focus ?

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  5. What is visual angle ?

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  6. An astronomical telescope uses lenses of power 10 D and 1 D. What is i...

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  7. Why is the aperture of objective lens of a telescope taken large ?

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  8. Why is power of objective lens of a telescope kept as small as possibl...

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  9. Why does Galilean telescope have a smaller field of view ?

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  10. In which, microscope or telescope, the difference in the focal lengths...

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  11. Why do we prefer a magnifying glass of smaller focal length ?

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  12. What do you understand by normal adjustment of a telescope ?

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  13. What is the distance between objective and eye lens of telescope in no...

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  14. Objective of a compound microscope should have small focal length. Why...

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  15. why should objective of a telescope have larger focal length ?

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  16. Can a terrestrial telescope be used for observing astronomical objects...

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  17. What is the main limitation of Galileo's telescope ?

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  18. What is the eye ring of a telescope or microscope ?

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  19. Is angular magnification of a telescope equal to ratio of diameters of...

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  20. What is meant by focal plane of a lens ?

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