Physics, asked by shivjot, 1 year ago

A person is not able to read from a book until he keeps it at 50 cm. Determine the power of corrective lens.

Answers

Answered by TPS
18
Since the person is able to read clearly from a distance of 50 cm, 
focal length required = 50 cm = 0.5m

Power =  \frac{1}{f}= \frac{1}{0.5}=2D

Power of corrective lens is 2D.

kaiser: U r missing that which lens is this actually and u have to explain what type of defect he is suffering from , u have to explain the questioner all the concepts of this problem
TPS: Only the power was asked. And I answered that.
Answered by Chotubls
14
The corrective lens should have focal length 50 cm = 0.5 m.
Thus, power of lens = 1/0.5 = 2 D
The person is suffering from hypermetropia.
In hypermetropia, the near point of the eye shifts from 25 cm to some greater distance.
A convex corrective lens is used to remedy this problem.

kaiser: Is this lens concave or convex and from which defect is the person suffering from????
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