TOPIC 6: OPTICAL INSTRUMENT – PHYSICS FORM TWO
Optical instruments: – are devices that use light through lenses to view objects.
These are the instruments which are used to help human eye to view small objects or distant objects more clearly
These include instruments like: –
➢ Simple microscope
➢ Compound microscope
➢ Telescope
➢ Lens camera
➢ Projector
➢ Human eye
The instruments use mirrors and lenses in their functions
The simple microscope
A microscope: – is an instrument which is used to view things that are too small to be seen
clearly by the naked eye.
Principle under which microscope works
The microscope works under the principle of the magnifying effect of a convex lens.
NEAR POINT
This is the least distance whereby an image appears clearest (sharpest)
Structure of simple microscope
A simple microscope consists of one biconvex lens. The object to be viewed is placed at the focal point or between the lens and the principal focus. The image formed is virtual and magnified.

