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12 grade physics others

Explain the working of compound microscope by focal length of convex lens:

Profile image of Aniket Singh
1 Year agoGrade
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Profile image of Askiitians Tutor Team
1 Year ago

A compound microscope is an optical instrument that uses two lenses to magnify small objects or specimens. It consists of an objective lens and an eyepiece (or ocular lens). The objective lens is closer to the specimen and provides the primary magnification, while the eyepiece lens further magnifies the image produced by the objective lens. The compound microscope works based on the principles of lenses and their focal lengths.

Here's how the working of a compound microscope can be explained using the focal length of the convex lenses:

Objective Lens:

The objective lens is a convex lens with a relatively short focal length. It is positioned very close to the specimen being observed.
When light from the specimen enters the objective lens, it converges to form a real and inverted intermediate image inside the microscope tube. The short focal length of the objective lens allows it to capture a wide angle of light from the specimen.
Intermediate Image:

The real and inverted intermediate image created by the objective lens is located inside the microscope tube. This image is magnified by the objective lens and contains the details of the specimen.
Tube Length:

The distance between the objective lens and the eyepiece is referred to as the tube length. This distance is typically adjustable to focus the image.
Eyepiece (Ocular Lens):

The eyepiece, or ocular lens, is another convex lens positioned at the end of the microscope tube, farthest from the specimen.
The eyepiece has a relatively longer focal length compared to the objective lens.
The eyepiece further magnifies the intermediate image formed by the objective lens. As light from the intermediate image enters the eyepiece, it converges to form a final image.
Total Magnification:

The total magnification of the compound microscope is the product of the magnification provided by the objective lens and the magnification provided by the eyepiece.
Mathematically, Total Magnification = Magnification of Objective Lens x Magnification of Eyepiece.
Viewing the Final Image:

The final image formed by the eyepiece is a magnified, virtual, and upright image of the specimen.
The observer looks through the eyepiece to view this image.
In summary, a compound microscope uses a combination of two convex lenses, with the objective lens close to the specimen and the eyepiece further from it. The objective lens forms a real intermediate image, which is further magnified by the eyepiece to produce a final virtual image for observation. The magnification of the compound microscope is determined by the focal lengths of these lenses and can be calculated as the product of the two magnifications.