RADIO WAVES
PREPARED BY MAHRU AWAL, ZAHEEN BINTE, MEHRAB KHAN, MAHDIN HASSAN
WHAT ARE RADIO WAVES?
Radio waves are a type of electromagnetic radiation. They are usually produced
by radio transmitters and can be received by radio receivers. Radio waves having
different frequencies contain various characteristics of propagation in the Earth’s
atmosphere. The long waves get diffracted around different obstacles and
follow the outline whereas the short waves reflect the ionosphere and get back
over the horizon of sky waves.
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PROPERTIES OF EM WAVES/RADIO WAVES
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They are transverse waves.
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They travel at 300,000,000 m/s in
vacuum.
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They can be reflected.
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They can be refracted.
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They transfer energy from one place to
another.
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They do not require a medium.
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USES
Radio waves are used for communication such as broadcasting television and
radio, communications and satellite transmissions. They are transmitted easily
through air. They can be reflected to change their direction. These properties
make them ideal for communications. Radio waves can be produced by
oscillations in electrical circuits. When radio waves are absorbed by a conductor,
they create an alternating current. This electrical current has the same
frequency as the radio waves. Information is coded into the wave before
transmission, which can then be decoded when the wave is received. Wireless
communication technologies such as television, mobile phones and radio
systems use this principle. Devices receive radio waves and convert them to
mechanical vibrations in the speaker to create sound waves.
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DANGERS
Exposure to very high RF intensities can result in heating of biological tissues
and an increase in body temperature. Tissue damage in humans could occur
during exposure to high RF levels because of the body's inability to cope with or
dissipate the excessive heat that could be generated.
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