2006-09-26 03:13:14 · 5 answers · asked by subra m 2 in Science & Mathematics ➔ Physics
Check here for a good answer http://en.wikipedia.org/wiki/Microwave
2006-09-26 03:18:33 · answer #1 · answered by curious george 5 · 0⤊ 0⤋
It's a misnomer dating from the WWII era: "microwaves" are electromagnetic radiation with wavelengths in the centimeter range---certainly not very "micro", but much smaller than the meter-long UHF (ultra-high frequency---again an exaggeration leading to a misnomer) waves initially used for radar.
Microwaves have frequencies between about 1 GHz and 30 GHz; that is, wavelengths between about 30 cm and 1 cm.
Shorter wavelengths are "millimeter waves" (not a misnomer), with wavelengths from 10 mm to about 1 mm.
Nowdays the term "microwave" tends not to be used---engineers will say "centimeter-wave" to refer to this band.
Microwave ovens heat food by emitting high intensity microwaves inside the oven cavity. Radiation at these frequencies is easily absorbed by the molecules in food.
2006-09-26 03:33:57 · answer #2 · answered by cosmo 7 · 0⤊ 0⤋
Tfhere is no 'hard and fast' answer but, generally, any electromagnetic wave with a wavelength less than about 30 cm (1 GHz) is considered a 'microwave'.
Doug
2006-09-26 03:19:25 · answer #3 · answered by doug_donaghue 7 · 0⤊ 0⤋
http://en.wikipedia.org/wiki/Microwaves
Similar to radio waves: electromagnetic.
2006-09-26 03:19:37 · answer #4 · answered by Anonymous · 0⤊ 0⤋
a electronic machine that warm ur food.......
2006-09-26 03:20:46 · answer #5 · answered by nickless 4 · 0⤊ 0⤋