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
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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’