1. Senior Science Information Systems
Part 2: Electromagnetic Spectrum

2. Electromagnetic Spectrum song video

3. Parts of a Wave

4. Types of Waves Electromagnetic Mechanical
Waves that don’t need a medium (solid, liquid or gas particles) to travel Eg. Light
Waves that need a medium (solid, liquid or gas particles) to travel Eg. Sound
Video

5. Mechanical Waves Longitudinal Transverse
The particles vibrate back and forth, parallel to the motion of a wave.
The particles in the wave vibrate up and down.

6. Frequencies Sound waves are described in frequencies.
Frequencies = pitch
Low frequency = low pitch
High frequency = high pitch
Frequency is the number of waves that pass a point per second
Frequency measured in Hertz

7. Properties of Electromagnetic Waves
Summarise Pg Properties of Electromagnetic Waves Intensity and distance Scattering and absorption Reflection and Refraction

8. Radio waves which includes: TV FM radio AM radio1
Identify the types of waves in the electromagnetic spectrum currently used for communication systems as
Visible light
Infra-red
Microwaves
Radio waves which includes: TV
FM radio
AM radio 3
Identify communication technologies that use energies from the electromagnetic spectrum for communication purposes

9. Electromagnetic Waves video

10. The Electromagnetic Spectrum

11. Visible Light
Visible light is created from multiple colours that each have their own wavelength.

13. Useful EMS Properties for communication technologies
Speed of Light (3x108 m/s) in a vacuum.
Its ability to travel in a straight line
Its ability to be reflected

14. The electromagnetic Spectrum
Summarise each of the types of waves and list communication technologies used with each. Pg
Radio waves
Microwaves
Infra-red
Visible Light
Ultraviolet
X-Rays
Gamma Rays

15. 2
Compare the advantages and disadvantages of using microwaves and radio waves in communication technologies

16. Using Microwave and radio waves in communication technologies
Advantages
Disadvantages
They can travel through air without requiring a medium such as wire
Because the waves travel in a straight line and can be reflected, they need transmitter and repeater stations to get around corners and objects.
They can broadcast to a huge audience over large distances. They don’t need people to be connected directly to one another or to the source of the information.
Broadcasting over a wide area means that a lot of energy is wasted; the receiver of the signal must be tuned into the correct frequency.
The frequency in transmission and reception of radio waves can be precisely controlled.
The most effective frequency ranges in the EM spectrum are limited; so there is a lot of competition in those frequencies.