Concepts Of Physics MCQ Edition [Volume 1]
- Exam
- Concepts Of Physics MCQ Edition [Volume 1]
- Subject
- Physics
- Chapter
- Optical Instruments
Concepts Of Physics MCQ Edition [Volume 1] · Physics · Optical Instruments
A compound microscope is composed of an objective with a focal...
A compound microscope is composed of an objective with a focal length of and an eyepiece with a focal length of . An object is positioned from the objective. Determine the separation between the lenses required for the microscope to project an inverted real image of the object onto a screen located behind the eyepiece.
Options
- A
- B
- C
- D
Correct answer
C.
Step-by-step solution
Using the lens formula for the objective lens:
Substituting and :
The image formed by the objective is virtual and is located in front of the objective.
For the eyepiece, the final image is real and is formed on a screen behind it. Using the lens formula for the eyepiece:
Substituting and :
The intermediate image acts as the object for the eyepiece and is located in front of it.
Let the separation between the lenses be . Since the intermediate image is in front of the objective, its total distance from the eyepiece is .
Therefore, .
Substituting and :
The image formed by the objective is virtual and is located in front of the objective.
For the eyepiece, the final image is real and is formed on a screen behind it. Using the lens formula for the eyepiece:
Substituting and :
The intermediate image acts as the object for the eyepiece and is located in front of it.
Let the separation between the lenses be . Since the intermediate image is in front of the objective, its total distance from the eyepiece is .
Therefore, .