What is a Compound Microscope is also the related topic to the geometrical optics.
Compound microscope has two converging sets of lenses
the objective and the eyepiece and is used to investigate
structure of small objects . Following are some
features of compound microscope:
Magnification can be determined through the ray diagram as
shown in Fig. 12.33. Objective forms a small image I1 inside
the focal point of eyepiece. This image acts as an object for
the eyepiece and the final larger image I2 is formed outside
the focal point of the objective.
The magnification of compound microscope is given by
M=L/fo(1+do/fe) where L is the length of compound microscope which is equal
to the distance between objective and eye piece, do is near
distance of object from eye, fo and fe are the focal lengths of
objective and eye piece respectively.
A compound microscope is used to study bacteria and other
micro objects. It is also used for research in several fields of
sciences like, Microbiology, Botany, Geology, and Genetics.
For your information
We see because the eye forms
images on the retina at the back of the eyeball.
Focal length ofmagnifying glass
On a sunny day, hold the magnifying glass, which is a converging lens, above a nonflammable surface, such as a sidewalk, so that a round spot of light is formed on the surface. Note where the spot formed by the lens is most distinct, or smallest. Use the ruler to measure the distance between the magnifying glass and the surface. This distance is the approximate focal length of the lens.
Objective lens has smaller
focal length, than the eyepiece.Distance between the
objective lens and the eyepiece is greater than f0+fe.It is used to see very small objects.