Q. 9

# The magnifying power of a simple microscope is given by , where *D* is the least distance for clear version. For farsighted persons, *D* is greater than the usual. Does it mean that the magnifying power of a simple microscope is greater for a farsighted person as compared to a normal person? Does it mean that a farsighted person can see an insect more clearly under a microscope than a normal person?

Answer :

For a farsighted person, the magnifying power of the lens is given by the ratio of

Where,

D= distance of the object and

f = focal length of the lens

Now, focal length remains same, but the distance D varies for a normal eye and farsighted eye.

Hence, the magnifying power of a farsighted eye will be more than that of a normal eye. Hence the

Farsighted person can see an insect more clearly under a microscope than a normal person.

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