The Electromagnetic Spectrum 9

Year 09 Topic 1: The Electromagnetic Spectrum.
9 Learning Opportunities From Monday the 30th of March until Friday the 1st of May
Learning Opportunity 9: How Radio Waves Move
This Learning opportunity has four tasks to do.
Target Time: 60 minutes.
Aim: learn how radio waves are used.

Task 1: Make four lists.

Copy and complete these four headings.
Then use the picture below to make a list for each heading.
Write down the things that are used. e.g. a phone is used for communication.
Use the video to help. You can start the video at 3:50.
Check your answers at the end of the blog.
Headings to copy
1) Carrying Information
2) Studying the Universe
3) Control signals
4) Navigation and radar.

Task 2:  Copy and complete a table.

Copy this table and then fill it in.
Use the information from the picture below to help.

NameInitialsAlso calledFrequency (Hz)Wavelength (m)Examples
Low frequencyLFLong wave300k1000Radio stations
Medium frequencyMedium wave
High  frequencyShort wave
Very high  frequency
Ultra high  frequency
Super high frequency3+GigaRadar
Task 3: Draw a diagram to show how long, medium and short wave radio waves are transmitted.

Draw a diagram to show how radio waves can be transmitted.
Make sure you show three different ways.
Use the information below to help.

Task 4: Check your answers and try the challenge!

Answers
Task 1: Here are the pictures groups together.

Task 2:

NameInitialsAlso calledFrequency (Hz)Wavelength (m)Examples
Low frequencyLFLong wave300k1000Radio stations
Medium frequencyMFMedium wave3MHz100Radio stations
High  frequencyHFShort wave30MHz10Radio stations
TV signals
Very high  frequencyVHFUltra-short300MHz1TV signals
Ultra high  frequencyUHFUltra-short300Mhz+1Mobile phone signals / Microwave ovens
Super high frequencySHFUltra-short3+Giga0.1Radar


Challenge Question:
Radio and TV signals were carried by analogue radio wave signals. However, they suffered from interference commonly known as ‘static’ noise on the radio or ‘snow’ on the tv. These are now being replaced by digital radio wave signals which are not affected by interference.

Why are digital signals not affected by interference, but analogue signals are? (4 marks)
Use information from the internet to help you answer the question.