NEET Exam > NEET Questions > If tube length of astronomical telescope is 1...
Start Learning for Free
If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objective
- a)100 cm
- b)10 cm
- c)20 cm
- d)25 cm
Correct answer is option 'A'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Most Upvoted Answer
If tube length of astronomical telescope is 105 cm and magnifying powe...
Free Test
FREE
| Start Free Test |
Community Answer
If tube length of astronomical telescope is 105 cm and magnifying powe...
Calculation of Focal Length of Objective Lens in an Astronomical Telescope
Given:
Tube length (L) = 105 cm
Magnifying power (M) = 20
Formula used:
Magnifying power (M) = focal length of objective lens (F) / focal length of eyepiece (f)
Calculation:
We know that magnifying power (M) = 20
Let the focal length of objective lens be F.
Using the formula,
M = F / f
20 = F / f
Since the normal setting is used, the final image is formed at infinity, and the eyepiece is adjusted to bring this image to the eye. Therefore, the final image is at the least distance of distinct vision (D) which is 25 cm.
Using the lens formula,
1/f = 1/D - 1/F
1/25 = 1/D - 1/F
1/F = 1/25 + 1/D
Substituting the value of F in the magnifying power formula,
20 = F / f
f = F / 20
Substituting the value of f in the lens formula,
1/F = 1/25 + 20/FL
Simplifying,
F = 100 cm
Therefore, the focal length of the objective lens in the astronomical telescope is 100 cm. Hence, option A is the correct answer.
Given:
Tube length (L) = 105 cm
Magnifying power (M) = 20
Formula used:
Magnifying power (M) = focal length of objective lens (F) / focal length of eyepiece (f)
Calculation:
We know that magnifying power (M) = 20
Let the focal length of objective lens be F.
Using the formula,
M = F / f
20 = F / f
Since the normal setting is used, the final image is formed at infinity, and the eyepiece is adjusted to bring this image to the eye. Therefore, the final image is at the least distance of distinct vision (D) which is 25 cm.
Using the lens formula,
1/f = 1/D - 1/F
1/25 = 1/D - 1/F
1/F = 1/25 + 1/D
Substituting the value of F in the magnifying power formula,
20 = F / f
f = F / 20
Substituting the value of f in the lens formula,
1/F = 1/25 + 20/FL
Simplifying,
F = 100 cm
Therefore, the focal length of the objective lens in the astronomical telescope is 100 cm. Hence, option A is the correct answer.
Attention NEET Students!
To make sure you are not studying endlessly, EduRev has designed NEET study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in NEET.
|
Explore Courses for NEET exam
|
|
Similar NEET Doubts
Top Courses for NEETView all
If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer?
Question Description
If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer?.
If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer?.
Solutions for If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for NEET.
Download more important topics, notes, lectures and mock test series for NEET Exam by signing up for free.
Here you can find the meaning of If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer?, a detailed solution for If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer? has been provided alongside types of If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice If tube length of astronomical telescope is 105 cm and magnifying power is 20 for normal setting, calculate the focal length of objectivea) 100 cm b) 10 cm c) 20 cm d) 25 cm Correct answer is option 'A'. Can you explain this answer? tests, examples and also practice NEET tests.
|
|
Explore Courses for NEET 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
|
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup