EM Spectrum Microwaves come between radio waves and

EM Spectrum • Microwaves come between radio waves and infrared on the EM spectrum. • Microwaves are one of the main types of electromagnetic radiation in the EM spectrum.

Our way of remembering the waves. Running. Men. In. Visible. Underwear. X-ray. Gentlemen radio micro infrared visible light ultraviolet x-ray gamma

Type of wave • A microwave is a transverse wave • Its perpendicular to the direction of travel.

Vacuum • All forms or electromagnetic radiation can travel through vacuums. • Some forms of EMR cannot pass through solid objects.

Wave length • Wave lengths range from one meter to one millimetre or equivalently with frequencies between 300 MHz(0. 3 GHz) and 300 GHz. • Microwaves have wavelengths approximately in the range of 30 cm.

Example of Emitters • Radar - a system for detecting the presence, direction, distance, and speed of aircraft, ships, and other objects, by sending out pulses of radio waves which are reflected off the object back to the source. • Microwave ovens

Uses of microwaves • Microwaves are used in microwave ovens, • Sending telephone messages - a phone call to Australia uses a microwave signal bounced off satellites in space, • Detecting speeding cars and motorcycles, • TV broadcasting, • Curing and drying plywood, • Treating muscle soreness, • Raising bread and doughnuts.

Dangers • Strong microwaves can boil water and we are 66% water. • Microwave ovens cook by heating the water molecules in food. We are mostly water so microwave ovens are designed to trap the waves inside and to start only when the door is closed. • Some microwaves pass through soft tissues, while some are absorbed by water molecules which heat up. Effects depend on wavelength and the strength of the radiation.