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Light is an
electromagnetic wave
similar to radio waves.
It has wavelength and
frequency.
It travels at
300,000,000 metres per
second.
Wavelength, frequency
and the speed of light
are related.
Wavelength x frequency =
the speed of light.
Different colours of
light have different
frequencies.
When a ray of light hits
a shiny surface it is
REFLECTED.
The angle of reflection
equals the angle of
incidence.
 When
light passes from one
transparent material to
another it is REFRACTED
(bent).
LENSES use
refraction.
CONVEX
lenses FOCUS a beam of
light to a point.
CONCAVE
lenses cause the
beam to DIVERGE.
The PRIMARY colours
which make up white
light can be separated
out by a glass PRISM.
Three of the primary
colours, RED, GREEN and
BLUE are used in the
colour television
system.
By mixing them most
other colours can be
made.
In the next diagram, red
and green make yellow,
green and blue make cyan
and red and blue make
magenta.
White is made by using
all three colours.
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