Starter Write down on the mini white board the types of electromagnetic wave used for communication.

(Hint) Remember the types: GateXUsually LetsIn Most Radiation

C/W 22nd November 2011Electromagnetic waves for

communicatingKeywords: carrier wave modulationObjectives:Must – State which types of electromagnetic waves are used for communication. (C/D)Should – Understand how information is carried using electromagnetic waves. (C/B)Could – Consider why we use specific electromagnetic waves for carrying information. (A/A*)

Complete the table whilst we are discussing the types of radiation.

Visible light, is used in fibre optics, and Morse code........

Microwaves are used in mobile phones, satellite TV, and sat-nav.

Not absorbed by the earths atmosphere, can be transmitted into space.

Radio waves are used for:Radio signals, terrestrial TV, and walky-talkies

Infra red is used for:Remote controls These waves can only travel short distances in air.

Low frequency and energy

High frequency and energy

Type of EM-wave

Communication Uses

Extra information

radio waves Radios, TV

microwavesSatnav, mobile phones, satellite TV

Can be transmitted into space.

infraredTV remotes Can only be

transmitted short distance

visibleFibre optics, Mores code

Hard to use if there is other light around

ultraviolet N/A

X-rays N/A

gamma rays

N/A

C/W 22nd November 2011Electromagnetic waves for

communicatingKeywords: carrier wave modulationObjectives:Must – State which types of electromagnetic waves are used for communication. (C/D)Should – Understand how information is carried using electromagnetic waves. (C/B)Could – Consider why we use specific electromagnetic waves for carrying information. (A/A*)

Crest / Peak

Time

Trough

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We are going to see how signals are actually broadcast as a wave..... Today’s Jazzy simulation

Recap on waves

How are sound waves broadcast through the air?1st we need a high frequency carrier wave....

Then we need to add the sound wave to it that we want to transmit

This gives us a modulated carrier wave

We are going to see how signals are actually broadcast as a wave.....

Pupils make their own waves using audacity

Complete questions on worksheet.

Plenary sketch on your mini white board

One type of e-mag wave used for communication and it’s application

Plenary sketch on your mini white board

The carrier wave

Sound signal to be broadcast

Modulated carrier wave

C/W 22nd November 2011Electromagnetic waves for

communicatingKeywords: carrier wave modulationObjectives:Must – State which types of electromagnetic waves are used for communication. (C/D)Should – Understand how information is carried using electromagnetic waves. (C/B)Could – Consider why we use specific electromagnetic waves for carrying information. (A/A*)

http://boswellsphysics.blogspot.com/

Or google ‘Boswells physics’