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Optical instruments
Uses of a compound microscope Materials: two convex lenses, hard
Compound microscopes have a wide manila sheets (coloured
range of applications in different aspects black), scissors, cutter,
of life. Some of the applications of
compound microscopes include: rubber disc, drill, a film
(a) Viewing laboratory small samples canister or a small plastic
FOR ONLINE READING ONLY
such as tissues and body fluids container, plywood, a
to check for infections caused by wooden stick
microorganisms;
(b) Studying micro-organisms and cells Procedure
in Biology experiments; and
(c) Observing the Brownian motion of 1. Use the black manila sheets to
fluid particles. Figure 6.6 shows a construct two tubes with slightly
student observing something using a different diameters such that the
compound microscope. smaller tube can slide into the larger
tube. Make sure each tube is longer
than the focal length of your lens.
2. Fix a lens to one end of each tube.
3. Slide the small tube inside the larger
tube such that you have one tube
with a lens on both sides of the tube.
4. Cover each side of the tube with a
rubber disc to protect the lenses.
5. Drill a hole at the bottom of a
canister.
Figure 6.6: Using a compound microscope 6. Insert the smaller tube into the open
end of the canister to about half the
Construction of a simple compound length of the canister. Ensure that the
microscope lens coincides with the hole drilled
One can easily construct a simple optical on the canister.
compound microscope. Activity 6.1 7. Use a square piece of plywood or
illustrates the steps for constructing a plastic to set your base. The square
simple compound microscope using local should have 10 cm sides. Attach a
materials.
white sheet at the middle of the base
to act as the stage.
Activity 6.1 8. Use a wooden stick to create a
Aim: To construct a simple vertical stand. Make the stand 2 cm
compound microscope tall.
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Physics Form 2 Final.indd 219 25/10/2025 10:28
