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प्रश्न
Name the following:
The photosensitive pigment present in the rods of the retina.
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उत्तर
Rhodopsin
संबंधित प्रश्न
A student suffering from myopia is not able to see distinctly the objects placed beyond 5 m. List two possible reasons due to which this defect of vision may have arisen. With the help of ray diagrams, explain
(i) why the student is unable to see distinctly the objects placed beyond 5 m from his eyes.
(ii) the type of the corrective lens used to restore proper vision and how this defect is corrected by the use of this lens.
(b) If, in this case, the numerical value of the focal length of the corrective lens is 5 m, find the power of the lens as per the new Cartesian sign convention
What is the other name for
myopia
What is short-sightedness? State the two causes of short-sightedness (or myopia). With the help of ray diagrams, show:
(i) the eye-defect short-sightedness.
(ii) correction of short-sightedness by using a lens.
An eye has a far point of 2 m. What type of lens in spectacles would be needed to increase the far point to infinity? Also calculate the power of lens required. Is this eye long-sighted or short-sighted?
Describe the mechanism of focusing the image of a distant object in your eye when you raise your head after reading a book.
Given below is a diagram depicting a defect of the human eye? Study the same and answer the question that follow :
Name the type of lens used to correct this eye defect.
Rewrite the following table so as to match second and third column with first column.
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Column I
|
Column II
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Column III
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(i) Myopia
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Old age problem
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Bifocal lens
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|
(ii) Presbyopia
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Nearsightedness
|
Concave lens.
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Give Reason:
Deficiency of vitamin A causes night blindness.
Choose the Odd One Out:
Which of the following statement is correct?
