A compound microscope consists of an objective lens of focal length \(2.0~\text{cm}\) and an eyepiece of focal length \(6.25~\text{cm}\) separated by a distance of \(15~\text{cm}.\) How far from the objective should an object be placed in order to obtain the final image at the least distance of distinct vision \((25~\text{cm})?\)
1. \(2.5~\text{cm}\)
2. \(0.5~\text{cm}\)
3. \(1.5~\text{cm}\)
4. \(5.0~\text{cm}\)

Subtopic:  Simple & Compound Microscope |
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Level 2: 60%+
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A person with a normal near point \((25~\text{cm})\) using a compound microscope with an objective of focal length \(8.0~\text{mm}\)  and an eyepiece of focal length \(2.5~\text{cm}\) can bring an object placed at \(9.0~\text{mm}\) from the objective in sharp focus. What is the separation between the two lenses?
1. \(7.20~\text{cm}\)
2. \(9.47~\text{cm}\)
3. \(2.50~\text{cm}\)
4. \(2.27~\text{cm}\)

Subtopic:  Simple & Compound Microscope |
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Level 2: 60%+
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A man with a normal near point \(25~\text{cm}\) reads a book with a small print using a magnifying glass: a thin convex lens of focal length \(5~\text{cm}.\) What is the ratio of maximum and the minimum angular magnification (magnifying power) possible using the above simple microscope?

1. \(\dfrac65\) 2. \(\dfrac56\)
3. \(\dfrac32\) 4. \(\dfrac23\)
Subtopic:  Simple & Compound Microscope |
 72%
Level 2: 60%+
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The linear magnification and angular magnification in the microscope have similar magnitude when the image is at a distance of:
1. \(35~\text{cm}\)
2. \(\infty\)
3. \(25~\text{cm}\)
4. none of these

Subtopic:  Simple & Compound Microscope |
 54%
Level 3: 35%-60%
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