A compound microscope is designed with two symmetric biconvex lenses. The objective lens is cut vertically, creating two identical plano-convex lenses. One of them is used in place of original objective lens. To retain same magnification keeping the object distance unchanged, the tube length has to be: 
1. increased two times
2. increased times \(\dfrac{3}{2}\) times
3. decreased two times
4. decreased times \(\dfrac{3}{2}\)
Subtopic:  Simple & Compound Microscope |
Level 3: 35%-60%
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In a microscope the objective is having focal length \(f_0=2~\text{cm}\) and eye-piece is having focal length \(f_e=4~\text{cm}.\) The tube length is \(32~\text{cm}.\) The magnification produced by this microscope for normal adjustment is:
1. \(50\) 
2. \(100\)
3. \(150\)
4. \(200\)
Subtopic:  Simple & Compound Microscope |
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In a microscope of tube length \(10~\text{cm}\) two convex lenses are arranged with focal length of \(2~\text{cm} \) and \(5~\text{cm}\). Total magnification obtained with this system for normal adjustment is \((5)^k.\) The value of \(k\) is:
1. \(2\)
2. \(5\)
3. \(3.5\)
4. \(4\)
Subtopic:  Simple & Compound Microscope |
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An object viewed from a near point distance of \(25~\text{cm},\) using a microscopic lens with magnification \('6’,\) gives an unresolved image, a resolved image is observed at an infinite distance with a total magnification double the earlier using an eyepiece along with the given lens and a tube of length \(0.6~\text{m},\) if the focal length of the eyepiece is equal to: 
1. \(15~\text{cm}\)
2. \(20~\text{cm}\)
3. \(22~\text{cm}\)
4. \(25~\text{cm}\)
Subtopic:  Simple & Compound Microscope |
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Level 3: 35%-60%
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Given below are two statements 

Assertion (A): For a simple microscope, the angular size of the object equals the angular size of the image.
Reason (R): Magnification is achieved as the small object can be kept much closer to the eye than \(25\) cm and hence it subtends a large angle.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. (A) is false but (R) is true.

Subtopic:  Simple & Compound Microscope |
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If we need a magnification of \(375\) from a compound microscope of tube length \(150~\text{mm}\) and an objective of focal length \(5~\text{mm},\) the focal length of the eyepiece should be close to:
1. \(22~\text{mm}\)
2. \(33~\text m\)
3. \(12~\text m\)
4. \(2~\text{mm}\)
Subtopic:  Simple & Compound Microscope |
Level 3: 35%-60%
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A compound microscope has an objective lens of focal length \(1~\text{cm},\) a tube length of \(20~\text{cm},\) and forms a magnified virtual image \(25~\text{cm}\) from the eyepiece; if its total magnification is \(100,\) the focal length of the eyepiece is:
1. \(3\) cm
2. \(6.25\) cm
3. \(10\) cm
4. \(15\) cm

Subtopic:  Simple & Compound Microscope |
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