Class 10 Exam > Class 10 Questions > If an eye has near point at a distance of 0.5...
Start Learning for Free
If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?
- a)2 dioptre
- b)3 dioptre
- c)1 dioptre
- d)2.5 dioptre
Correct answer is option 'A'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
If an eye has near point at a distance of 0.5m, What is the power of l...
Since the person can't read an object at a distance of 50 cm, therefore focal length must be 0.5 m. We know that ;
P = 1/f , hence, P = 1/0.5 = 2 dioptre.
P = 1/f , hence, P = 1/0.5 = 2 dioptre.
Most Upvoted Answer
If an eye has near point at a distance of 0.5m, What is the power of l...
Explanation:
Power of lens is defined as the reciprocal of the focal length of the lens.
Formula for power of lens is:
P = 1/f
where P is power of lens and f is focal length of the lens.
Given, near point of eye = 0.5 m
For a normal eye, near point is considered to be at a distance of 25 cm or 0.25 m.
So, in this case, the near point is farther than the normal near point. This condition is known as hypermetropia or long-sightedness.
To correct this condition, a converging lens is used.
Converging lens has positive power.
Formula for focal length of a lens is:
1/f = (μ - 1) (1/R1 - 1/R2)
where μ is refractive index of lens material, R1 is radius of curvature of first surface, and R2 is radius of curvature of second surface.
For a thin lens, R1 and R2 are assumed to be much larger than the thickness of the lens.
So, the formula becomes:
1/f = (μ - 1) / R
where R is the radius of curvature of the lens surface.
For a converging lens, R is positive.
Let the power of lens required to correct the condition be P.
Then, using the formula for power of lens and the formula for focal length of a lens, we get:
P = 1/f = (μ - 1) / R
Here, μ is taken to be 1.5, which is the refractive index of the lens material used in most corrective lenses.
Substituting the values, we get:
P = (1.5 - 1) / R
Since the near point is farther than the normal near point, the focal length of the lens required is positive.
So, the radius of curvature of the lens surface is also positive.
We do not know the exact value of R, but we know that it is positive.
Therefore, the power of lens required is positive.
Option A: 2 dioptre is the correct answer.
Free Test
| FREE | Start Free Test |
Community Answer
If an eye has near point at a distance of 0.5m, What is the power of l...
Since the person can't read an object at a distance of 50cm...therefore focal length must be 0.5m
we know that P=1/f... hence P=1/0.5=2 dioptre(S.I unit of power)
we know that P=1/f... hence P=1/0.5=2 dioptre(S.I unit of power)
Attention Class 10 Students!
To make sure you are not studying endlessly, EduRev has designed Class 10 study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Class 10.
|
Explore Courses for Class 10 exam
|
|
Similar Class 10 Doubts
Top Courses for Class 10View all
If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer?
Question Description
If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer? for Class 10 2024 is part of Class 10 preparation. The Question and answers have been prepared according to the Class 10 exam syllabus. Information about If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 10 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer?.
If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer? for Class 10 2024 is part of Class 10 preparation. The Question and answers have been prepared according to the Class 10 exam syllabus. Information about If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 10 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer?.
Solutions for If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 10.
Download more important topics, notes, lectures and mock test series for Class 10 Exam by signing up for free.
Here you can find the meaning of If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer?, a detailed solution for If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer? has been provided alongside types of If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice If an eye has near point at a distance of 0.5m, What is the power of lens required to correct it?a)2 dioptreb)3 dioptrec)1 dioptred)2.5 dioptreCorrect answer is option 'A'. Can you explain this answer? tests, examples and also practice Class 10 tests.
|
|
Explore Courses for Class 10 exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up
within 7 days!
within 7 days!
Takes less than 10 seconds to signup