1. Radio waves

• By Elmer George

2. What is a radio wave?

Radio waves are part of the electromagnetic spectrum which is a range of all frequencies of electromagnetic radiations.

Different frequency bands transmit radio waves differently.

They are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum.

Radio waves have frequenciesfrom 300 GHz to as low as 3 kHz

They vary in wavelength fromaround a millimetre to 100,00 km

3. How does a radio wave work?

Radio waves are planned to reach local, regional, national and sometimes international areas.

AM radio waves use low frequency ground waves so that they can follow the curvature of the earth.

FM radio waves use direct waves that travel in straight lines, so they use radio transmitters for long distances.

Radio transmitters are electronic devices which with the use on antennas produce radio waves.

4. Electromagnetic spectrum.

Electromagneticspectrum is a rangeoffrequenciesof electromagneticradiation, it extendsfrom a low frequencyused for radioto gamma radiation.

5.

The Electromagnetic spectrum consists of:

radio

infrared

ultraviolet

x-ray

gamma ray

6. Television

Television travels at the same speed of light roughly 300.000 km/s or 186.000 miles per second.

Television is a telecommunication medium for transmitting and receiving moving images, that can be black and white or in colour with or without sound.

They have been commercially available since the late 1920s.

It has become a necessity in any household as it is a major tool used in advertising, a source of entertainment and news since the 1970s.

DVDs, Blue ray and video cassettes have made televisions frequently used for watching recorded and broadcast material.

Television recently has become available via the internet such as BBC iplayer and youtube.

7. Microwaves

Microwaves have a wave length that is short so it can be measured in centimetres.

Microwaves can also be used for transmitting information because they can penetrate light rain, haze, snow, clouds and smoke.

Microwaves are also used for radars, it was created to determine the range and detect objects by transmitting short bursts of microwaves, then the object is recorded.

8. Wi-Fi

Wifi is wireless networking, it gives you the ability to connect to a PC or network using a radio signal, it is perfect for home and office use.

Wifi comes in two speeds 802.11b this transfers data and 11 megabits per second and the more recent 801.11g which goes up to 54 megabits per second.

Compared to bluetooth wifi is much faster as bluetooths speed is 0.57 megabits per second.

wifi has a typical range of 500 feet indoors, laptops and even mobile phones come with wifi built in these days because of the growing use of it.

Wifi has become so common that it is offered in most public places even fast food restaurants for example mcdonalds.

9. Infrared Waves

Infrared waves are in between the visible and microwave part of the electromagnetic spectrum.

near infrared light is closer in wave length to visible light, and far infrared is closer to the microwave part of the electromagnetic spectrum.

far infrared waves produce heat, they are thermal so we feel this type if wave daily. for example sunlight, radiator and a fire.

near infrared are shorter and do not produced any heat, they are the waves used by your television remote.

humans produce infrared waves at normal bodytemperature.

10. Reference

http://science.hq.nasa.gov/kids/imagers/ems/radio.html- Radio wave information

http://science.hq.nasa.gov/kids/imagers/ems/infrared.html- Infrared information

http://www.filesaveas.com/wifi.html information- Wifi information

http://en.wikipedia.org/wiki/Television- Television information