Chapter 2: The Human Eye and the Colourful World

Q&A -Ask Doubts and Get Answers

Q
The Human Eye and the Colourful World

Question:

A person needs a lens of power –5.5 dioptres for correcting his distant vision. For correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal length of the lens required for correcting (i) distant vision, and (ii) near vision?

Answer:

(i) For distant vision

Here, P= -5.5 D We know,

P = frac{1}{f}

-5.5 = frac{1}{f}

f = frac{1}{-5.5}

f = -0.181 m

 

(ii) For near vision

Here, P = +1.5 D

We know,

P = frac{1}{f}

1.5 = frac{1}{f}

f = frac{1}{1.5}

f = 0.667 m


Related Questions for Study

What our students and parents say about us!

Choose EduSakshamยฎ
Embrace Better Learning

edusaksham-mobile-app