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Electromagnetic spectrum…read more

Slide 2

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The electromagnetic spectrum is the term given to the groups of different
radiations. Radiation is energy that travels and spreads out as it goes
thought the spectrum. Radiation travels though space in particles and waves.
The order of the electromagnetic is:
1.Radio waves 4.Visible light
2.Microwaves 5.Ultra violet
3.infra red radiation 6.X-rays
7.Gamma rays
As you go down the electromagnetic spectrum the frequency and energy of
the waves increases and the wavelength decreases.
The spectrum is arranged by the frequency of its waves, from the smallest
frequency to the largest frequency. As the frequency increases the wave
length decreases as you go along the electromagnetic spectrum.…read more

Slide 3

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Radio waves
Radio waves:
Radio waves have the smallest frequency and the largest wavelength.
The wavelength can vary between 1 mm to 100 000 km. The radio
waves are used in forms of communication like phones, radios, TV etc.
The radio waves can penetrate through materials like wood, bricks,
concrete but cannot travel through electric conductors. The radio
wave is easy to transmit and the aerials pick up the signals very well.
The range of frequency's available for the communication companies
is very limited, so it is very hard to use the radio waves with the larger
Large amounts of radio waves can cause cancer and leukaemia.…read more

Slide 4

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Microwaves :
The frequency of microwaves can vary from 0.3 HTz to 300 HTz and is
second on the electromagnetic spectrum. The radiation can pass
through non metals like plastic and glass but reflects off metal
objects. Microwaves can cause water and fat molecules to vibrate
therefor heating the substance up. Microwaves can be modified to
carry more than one signal at a time. The microwave can be absorbed
by many normal things like rain, concrete etc. and to receive the
signals you need special aerials.
Being exposed to microwaves for a long period of time can cause
cataract (an eye disease that can cause blindness.) also some
microwaves from mobile phones can cause brain damage.…read more

Slide 5

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Infra red radiation
Infra red radiation:
Infra red radiation is very important in a persons life because this
radiation is basically heat. The infra red radiation is thermal meaning
that it gives off heat, like heat from the sun, fire etc. Some of the
thermal radiation can be felt by the human skin. The shorter infra red
waves are not hot at all, and skin cant even feel the thermal energy
give off by the radiation. Infra red radiation is also given off by
humans. Many devises like remote controls, TV use infra red radiation.
The dangers of infra red radiation is the risk of overheating an object
and occasionally over heating your body.…read more

Slide 6

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Visible light
Visible light :
Our eyes can detect only a tiny part of the electromagnetic spectrum
and tat is the visible light. Light waves are given off by anything that is
hot enough to glow.
Light waves can be used in light bulbs and we use the light from the
sun to see things. We use the wavelength form the sun to see and
observe our environment.
Too much light can damage the retina in the eye.…read more

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