electromagnetic communication21 mar class listseating plan electromagnetic communication 21 mar 2012

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

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Radio

Electromagnetic communication 21 Mar

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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.