KS3 Science - Electromagnetic Spectrum: Radio

 Heinrich Hertz proved the existence of radio waves in the late 1880s

Starting from British physicist James Maxwell’s theory of electromagnetic waves, Italian electrical engineer Guglielmo Marconi created the  first practical radio transmission and reception system c 1894.

Radio Controlled Toy

• The primary application of radio waves is in radio and television broadcasting.
• Transmission methods may vary from satellite to radio transmission towers
• Radio communication is also used by military during peacetime and wartime 
• Remote control toys, garage openers apply radio frequency technology
• Cellular phones, wireless clocks etc
• Space communication is also done using this technology
• Magnetic Resonance Imaging (MRI) uses radio waves to produce cross-sectional images of organs and other internal body structures thus avoiding exposure to radiations like X-rays
• RFID tags identify items by transmitting radio waves which can be picked up by a reader.

Sweetsearch a handy web search tool...

* Radio waves constiute waves in the electromagnetic spectrum at frequencies lower than microwaves.

* Wavelengths range from few thousand meters to around 30 cm and correspond to frequencies from 3 Hz to as high as 1GHz

Source: http://www.britannica.com/EBchecked/topic/488998/radio-wave

RFID tagged Passport of Great Britain 

RFID tag on a book in Senior Library