Page 10 - SCERT Kerala State Syllabus 8th Standard Basic Science Textbooks English Medium Part 1_Neat

The function of a microscope is to magnify objects, isn’t it?
Lenses are fixed in the microscope for this purpose. Name
the parts where lenses are fixed.

Microscopes in which more than one lens is used are called
compound microscopes (Fig 1.1).

Analyse the given description on the basis of indicators
and note down your inferences in the science diary.

Arrangement of light in a microscope
In the microscope, the part fixed below the stage is to Magnification
reflect light on the material to be observed. This power
arrangement which is fixed in a metal ring has two
planes, a plane mirror to reflect sunlight and a
concave mirror to reflect artificial light. The lens in
the condenser that is fixed on the lower side of the
stage focuses light on the material to be observed.
Diaphragm, a part of the condenser, helps to regulate
the intensity of light.

Indicators
Why is a mirror fixed in a microscope?
The magnification power of
Why do we use a slide made of glass to place the objective lenses are marked
material to be observed? as 10x and 45x. Such markings
Have you understood the basic concepts of a microscope? can be seen in eyepiece too.
Accuracy in using a microscope can be attained only The magnification power of a
microscope is the result of
through practice. Learn to operate a microscope using the
multiplying the numbers seen
permanent slides available in your science lab.
in the objective lens and the
Let's prepare the observation material eyepiece.
Preparation of observation material requires much accuracy
and patience. Observe the illustration that shows the stages
for the preparation of the slide to observe plant cells. Then
prepare a slide by taking the cross section of the root of
plantain.

Basic Science VIII 9