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प्रश्न
Have a look at the posture of this woman who is reading a book and answer the questions which follow:
What kind of looking glasses she needs?
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उत्तर
Looking glasses with the concave lens are required here.
संबंधित प्रश्न
In a Std. X class out of 40 students 10 students use spectacles, 2 students have positive power and 8 students have negative power of lenses in their spectacles.
Answer the following questions:
(1) What does the negative power indicate?
(2) What does the positive power indicate?
(3) Generally which type of spectacles do most of the students use?
(4) What defect of eyesight do most of the students suffer from?
(5) Give two possible reasons for the above defect.
Name one defect of vision (or eye) which cannot be corrected by any type of spectacle lenses.
What is the far point of a person suffering from myopia (or short-sightedness)?
What is long-sightedness? State the two causes of long-sightedness (or hypermetropia). With the help of ray diagrams, show:
(i) the eye-defect long-sightedness.
(ii) correction of long-sightedness by using a lens.
Name the following:
The photosensitive pigment present in the rods of the retina.
What eye defect is hypermetropia? Describe with a ray diagram how this defect of vision can be corrected by using an appropriate lens.
Given below is a diagram depicting a defect of the human eye? Study the same and answer the question that follow:
Give two possible reasons for this defect of the eye in human beings.
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.
The near point of the eye of a person is 50 cm. Find the nature and power of the corrective lens required by the person to enable him to see clearly the objects placed at 25 cm from the eye?
When do we consider a person to be myopic or hypermetropic? Explain using diagrams how the defects associated with myopic and hypermetropic eye can be corrected?
