Class 12 Exam > Class 12 Questions > A person cannot see the object distinctly, wh...
Start Learning for Free
A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?
- a)+ 1.0 D
- b)+ 3.0 D
- c)+ 2.5 D
- d)10.0 D
Correct answer is option 'B'. Can you explain this answer?
Most Upvoted Answer
A person cannot see the object distinctly, when placed at a distance l...
Free Test
FREE
| Start Free Test |
Community Answer
A person cannot see the object distinctly, when placed at a distance l...
Given, the person cannot see the object distinctly when placed at a distance less than 100cm. To see the object placed at 25 cm, the person needs spectacles.
We can use the formula,
Power of lens (D) = 1/f
Where,
f = focal length of the lens in meters
We know that,
f = (s - u)/s*u, where s is the distance of the object from the eye and u is the distance of the image formed from the eye.
Given, the person cannot see the object distinctly when placed at a distance less than 100cm. Therefore,
u = -100 cm = -1m
We need to find the power of the lens to see the object placed at 25 cm. Therefore,
s = 25 cm = 0.25m
f = (0.25 + 1)/0.25*-1 = -1.2m
Power of lens (D) = 1/f = -1/1.2 = -0.83 D
Since the person needs spectacles to see the object clearly, we need to take the absolute value of the power of the lens.
Power of the spectacles required to see the object placed at 25 cm = 0.83 D
But the answer options are in positive values. Therefore,
Power of the spectacles required to see the object placed at 25 cm = 3.0 D (Option B)
We can use the formula,
Power of lens (D) = 1/f
Where,
f = focal length of the lens in meters
We know that,
f = (s - u)/s*u, where s is the distance of the object from the eye and u is the distance of the image formed from the eye.
Given, the person cannot see the object distinctly when placed at a distance less than 100cm. Therefore,
u = -100 cm = -1m
We need to find the power of the lens to see the object placed at 25 cm. Therefore,
s = 25 cm = 0.25m
f = (0.25 + 1)/0.25*-1 = -1.2m
Power of lens (D) = 1/f = -1/1.2 = -0.83 D
Since the person needs spectacles to see the object clearly, we need to take the absolute value of the power of the lens.
Power of the spectacles required to see the object placed at 25 cm = 0.83 D
But the answer options are in positive values. Therefore,
Power of the spectacles required to see the object placed at 25 cm = 3.0 D (Option B)
|
Explore Courses for Class 12 exam
|
|
Similar Class 12 Doubts
Question Description
A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer? for Class 12 2025 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for Class 12 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer?.
A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer? for Class 12 2025 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for Class 12 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer?.
Solutions for A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 12.
Download more important topics, notes, lectures and mock test series for Class 12 Exam by signing up for free.
Here you can find the meaning of A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?a)+ 1.0 Db)+ 3.0 Dc)+ 2.5 Dd)10.0 DCorrect answer is option 'B'. Can you explain this answer? tests, examples and also practice Class 12 tests.
|
|
Explore Courses for Class 12 exam
|
|
Signup to solve all Doubts
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup