2. LIGHT: is the electromagnetic radiation that is
visible to the human eye, and is responsible for
the sense of sight.
There are two kind of light sources:
Natural Artificial
3. Light rays have
different frequencies
which are measured
by their wavelength,
different frequencies
means different
colors. Note:
frequency refers to
number of crests of
waves of same
wavelength that pass
by a point in one
second.
COLOURS
4. Light rays that are below vision range are
called INFRARED RAYS and light rays that are
above vision range are called ULTRAVIOLET
RAYS.
5. Is a phenomenon that happens when a ray of
light goes through a transparent surface such as
glass or water.
Transparent
surfaces slow
down the light
that goes through
it and gives the
effect that the
objects are bent.
REFRACTION
6. REFLECTION
Reflection is when light bounces off an object. If the
surface is smooth and shiny, like glass, water or
polished metal, the light will reflect at the same angle
as it hit the surface. This is called specular reflection.
7. INTERFERENCE
Is a phenomenon in which two waves
superpose to form a resultant wave of greater
or lower amplitude.
Resultant wave
Wave 1
Wave 2
Constructive
interference
Destructive interference
8. An optical fiber cable is a cable containing one
or more optical fibers that are used to carry
light.
Optical fiber cables
have a transformer
on each end that
converts the
electrical waves in
light waves to
transmit more
information faster
and more easily.
