Question

the near point of long sighted person is 50 cm what lens should be used in order to read from a distance of 25cm in the spectacles find power also of the lens ?
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Answer 1

Explanation:

1/f = 1/v -1/u

1/f = 1/25 - 1/50

1/f = (50-25)/(25 X50)

1/f =25/(25x 50)

1/f = 1/50

f= 50,it is positive that means using converging lens

p = 1/f = 100/50=2dioptre