electromagnetic communication21 mar class listseating plan electromagnetic communication 21 mar 2012
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Electromagnetic communication 21 Mar
Class listSeating Plan
Electromagnetic communication
21 Mar 2012
Electromagnetic communication 21 Mar
Class listSeating Plan
Learning Objectives
• Be able to describe: how radio waves , microwaves and infra-red radiations can be used for communication.– Level 5-7
• Be able to describe why different radiation is used for different communication.– Level 3-5
Electromagnetic communication 21 Mar
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Light tech
• Compile a list of different gadgets and gizmo’s that use the following Electromagnetic radiation.(try to link the radiation to the gizmo if you can)
– Visible light Infra red Microwave– Radio Ultraviolet
Electromagnetic communication 21 Mar
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Light waves have an electric component
Electromagnetic communication 21 Mar
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Electromagnetic waves need a medium to travel through
Electromagnetic communication 21 Mar
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When an electromagnetic wave passes over a conductor something happens
Electromagnetic communication 21 Mar
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In space noone can hear you scream
Electromagnetic communication 21 Mar
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Electromagnetic communication 21 Mar
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Radio
Electromagnetic communication 21 Mar
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Radio
Electromagnetic communication 21 Mar
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Radio
Electromagnetic communication 21 Mar
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Radio• Our first means of wireless communication, invented by a local.
Marconi.
• Very long wavelength (km)
• Very low frequency (kHz)
• Can pass through a lot of materials (people, walls etc.)
• Can bounce off the atmosphere– Can be good– Can be bad
Electromagnetic communication 21 Mar
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Radio
Electromagnetic communication 21 Mar
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Microwaves
• Used in Satellites – they pass through the atmosphere more easily.
• Much smaller wavelength (cm)
• Much higher frequency (MHz – GHz)
• Microwaves are absorbed by metals much like radio waves.
Electromagnetic communication 21 Mar
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Infra-red and Visible
Electromagnetic communication 21 Mar
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Infra-red and visible
• Used in Fibre optics:
• Law of refraction – Total internal reflection
Electromagnetic communication 21 Mar
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Electromagnetic communication 21 Mar
Class listSeating Plan
Radio
Electromagnetic communication 21 Mar
Class listSeating Plan
6 mark question
• Explain using what you know about Electromagnetic radiation, which type of radiation is used for TV, Satellite and Endoscopes and why. For full marks you need to explore the relationship between wavelength of EM radiation and transparency of media.