Why microwave frequency is called "Microwave"?
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The web links would probably give you this eventually, but the short answer is a microwave is called a microwave because it uses electromagnetic waves with a wavelength on the order of a "micron" (which is 0.000001 meter, or 0.001 mm, or 1000 nanometers, or 10000 Angstroms)
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In 1965 two American physicists at the Bell Telephone Laboratories in New Jersey, Arno Penzias and Robert Wilson, were testing a very sensitive microwave detector. (Microwaves are just like light waves, but with a wavelength of around a centimeter.) Penzias and Wilson were worried when they found that their detector was picking up more noise than it ought to. The noise did not appear to be coming from any particular direction. First they discovered bird droppings in their detector and checked for other possible malfunctions, but soon ruled these out. They knew that any noise from within the atmosphere would be stronger when the detector was not pointing straight up than when it was, because light rays travel through much more atmosphere when received from near the horizon than when received from directly overhead. The extra noise was the same whichever direction the detector was pointed, so it must come from outside the atmosphere. It was also the same day and night and throughout the year, even though the earth was rotating on its axis and orbiting around the sun. This showed that the radiation must come from beyond the Solar System, and even from beyond the galaxy, as otherwise it would vary as the movement of earth pointed the detector in different directions.
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I believe bluetooth uses 2.4 GHz, but I could be wrong about that.\n\nBasically the modern wireless standards and cellphones use frequencies which are not ionizing. Higher frequencies, with more energy, can zap the electrons off atoms and that can cause medical problems. Non-ionizing radiation just sort of wiggles the atoms around. (These are technical terms of course...)\n\nWhat confuses people sometimes is that the 2.4 GHz is also the frequency for a microwave oven. But a microwave has a very powerful radio source inside so it wiggles the atoms in your pot roast, or whatever, a lot, in order to heat them.\n\nBluetooth being so short range is even weaker, I believe, than a typical cellphone. \n\nYou're not going to heat you brain with a cell phone. So the chance of any danger is extremely slight. (Of course that danger also depends on how much you use the phone.)
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Microwaves are not ionizing radiation, but they will cause your flesh to cook if you are exposed to enough of it for long enough. They will cause burns.
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1. microwaves heat water faster than boiling it over a heat source.\n\n2. microwaves have a more direct effect on an atom, since the energy is transferred directly form the MW to the atom, unlike the boiling water where it is transferred from heat source to water to the thing (w/ enzymes). the longer path means longer time.\n\n3. since the atoms (or molecules for enzymes) directly interact with the MWs, they are more likely to be destroyed than when boiling water is used. Hence the shorter time to ensure deactivation, and not destruction, is achieved
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Almost anything with an electric motor. (the starter on your car)\nElectric locks, relays (that clunk when you turn on the microwave)\nThe microwave itself (something called a magnetron inside which makes the radar waves that cook the food).
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That's completely untrue! There is a microwave at almost anybody's house in Japan. It's very commonly used to heat food.\nThere are people who are concerned about the electromagnetic wave that a microwave releases while it's in use. I think it's same as a microwave in the states. (my mom tells me to stay away from the microwave while heating food! She's too conscious!!) This electromagnetic wave are in doubt that it could cause some damage in our brain. But it's not proved yet. And most people don't really care. \nSo everyone uses microwave for heating food in Japan! I'm sure of this.
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Television signals are broadcast using the FM (Frequency Modulation) method; only radio signals are broadcast in AM (Amplitude Modulation).\n\nThe earliest signals were broadcast as AM signals.  They are still used when long distance is required, since these signals can be bounced off the Ionosphere and therefore travel beyond the horizon, but this method of broadcasting doesn’t create as clear a signal so it is normally only used for voice.\n\nFM signals are used for stereo radio and televisions signals because they broadcast a clearer signal.  They can also support signals of a higher bandwidth, packing more of a data stream into one channel.\n\nSo what is FM and AM?  A radio or television signal is sent out on a sine wave pattern.  Imagine looking at a series of ocean waves from the side.  You will see the water go up and down in the same regular pattern.  A sine wave is very similar it starts at zero and goes up to a certain height, then it drops to zero, and goes down to that same height, then it goes back up to zero, then up to the same height and it continues.  The height of the wave is called the amplitude, the length of one cycle is called the frequency, and the spot on the electromagnetic spectrum where it is broadcast at is determined by the channel or the spot on the radio dial where you have tuned in the signal (this is the broadcast band and sometimes it is called the frequency; a left over from the days of on AM signals).  This is commonly called the radio or television band.  The signals are considered a band because you need two signals for stereo sound, and more for all the picture data.\n\nSo an AM signal has higher wave heights and lower wave depths on the signal.  The signal is encoded on the wave frequency between each wave high and low point.  Send it fast enough and you can carry audio signals, like voice and mono music.  If you tried to broadcast two signals on the same AM band then you don’t get the sine wave again; you end up with each signal interfering with itself creating just noise.  The AM signals simply add together making stronger signals, but they cancel out the information encoded into that signal.  When you use a shortwave, CB (Citizens Band) or police radio you are broadcasting with an AM signal.  If two people try to talk then they either interfere and cancel each other out, or the more powerful (or closest) signal “walks” over the other signal so you only hear on voice.  This is why when talking on a short wave radio you need to say “over” so the other person knows that they can talk now.  The advantage with this type of system is that you can use the idiosyncrasies of our atmosphere to bounce a signal off the Ionosphere.  Since there is a clear difference between each atmospheric layer it is possible to bounce the signal around (http://en.wikipedia.org/wiki/Ionospheric_reflection).\n\nLook at this picture:  http://upload.wikimedia.org/wikipedia/en/f/f1/Voice_waveform_and_spectrum.png\nOn the chart with the green lines the difference between the base line and the height of each green wave is the amplitude. \n\nFM signals work in a different fashion.  The signal is encoded in the height and depth of each wave so you can broadcast several signals on the same band without having them interfere with each other.  This lets you broadcast a stereo signal to a FM radio.\n\nTelevision signals are broadcast this way as well so that stereo sound can be sent (in the early days of TV stereo wasn’t used).  This broadcast method also allows the more complex data of the television signal to be sent along with the audio signals. But, this still isn’t enough so TV signals are broadband; several signals are sent at the same time across a series of bands, close together on the spectrum, so all the information gets through.  When you tune your TV you are actually selecting several bands grouped together which carry all the signals required.  If you tried this with an AM band then you would ha
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A microwave is a device that creates HIGH POWER microwave RADIATION. If this stuff gets to you, then there is a possibility of cancer.  Remember the deal with cellphones and cancer?\n\n    Inside the microwave you'll notice there is a steal mesh.  You see it in front of your microwave(It's got millions of holes in it).  This mesh is called a Faraday cage. What this mesh does is that it is actually protects you, by "blocking" the microwaves from escaping.  Remove the mesh and the microwaves have a chance to escape into the environment.\n\n    Cellphones also create microwaves.  But the microwaves coming from your cellphone, pale in power compared to the microwaves coming from the oven.  \n\n    Remember that radiation get's embedded into your skin.  It stays there for a long time, and eats away at you slowly.
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Microwaves are highly targetable, that is their primary benefit. Microwaves were developed for use with radar, thus early microwaves were called radar ranges.\nThat being said, there will always be a little leakage, not enough to be dangerious, at least no more dangerious that the other megajoules of microwaves coursing through your body thoughout the day from radars, radar detectors, alarm systems communications arrays, etc.
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the short answer is no. \n\nA microwave does not pass heat to the food the way an oven does, instead a microwave utilizes the principle of dielectric heating. basically what this means is that the microwave (which is an invisible form of everyday light) is made of an electromagnetic wave. This electromagnetic wave is passed throughout the cooking chamber where it interacts with the food. Heres the thing...most molecules are dipoles which means that they have a negative and a positive side to them.....the electromagnetic microwave interacts with the molecules and makes them dance to line up with the feild. Its this motion of the molecules that creates the heat. Microwaves have been designed to interact primarily with water molecules because most food has some water in it. This doesn not mean that other dipolar molecules in plates, cups or utensiles would not try to align themselves with wave. If they did then they would have been heated by the microwave. In fact, any molecular movement caused by the microwave could be considered heat and I'm sure that this movement is not limited to water.
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The microwave auditory effect, also known as the microwave hearing effect or the Frey effect, consists of audible clicks induced by pulsed/modulated microwave frequencies that are generated directly inside the human head without the need of any receiving electronic device. The effect was first reported by persons working in the vicinity of radar transponders during World War II. These induced sounds are not audible to other nearby people. The microwave auditory effect was later discovered to be inducible with shorter-wavelength portions of the electromagnetic spectrum. During the Cold War era, the American neuroscientist Allan H. Frey studied this phenomenon and was the first to publish (1961) information on the nature of the microwave auditory effect; this effect is therefore also known as the Frey effect.\n\nResearch by NASA in the 1970s showed that this effect occurs as a result of thermal expansion of parts of the human ear around the cochlea, even at low power density. Later, signal modulation was found to produce sounds or words that appeared to originate intracranially. It was studied for its possible use in communications but has not been developed due to the possible hazardous biological effects of microwave radiation. Similar research conducted in the USSR studied its use in non-lethal weaponry.
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f=1/period=1x10^9 hz= 1 GHz\n\n1 GHz- microwave/radio frequency (rf)
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It passes right through.   \n\nThe friction of the waves passing through is why food gets hot in the microwave.  Cell Phones and Wi-Fi do not have much power behind them is why don't cook but if you stand right in front of a microwave communication tower emitter you will be one roasted dude.  The guy that invented the microwave oven had discovered the application while working on radar arrays for the military and a candy bar in his shirt pocket had suddenly melted while he was standing near the emitter.\n\nThe dad of a friend of mine got mad one day and decided to throw a microwave into the street.  It smashed the door but still worked when we plugged it back in.  Even with the door open !  It felt pin-prickly and unpleasant if you put your hand in while it was running--  Don't try this at home !!
19985
Ar e you talking about a microwave oven?  It is very dangerous to put metal in microwaves.  The radiation used in a microwave is designed to be a specific wavelength that is preferentially absorbed by water.  But meatl can greb all wavelengths, and via the photoelectric effect, it can turn the microwave photons into electrical sparks that could start a fire.
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microwave are the same as radio waves \nsatellite are when you transmit to a satalite \nradio waves are basicly any sound. \nlaser is energy in the form of light, \noptical fiber is used for telephones which transport light instead of radio waves, which is much faster\ninfared it think is just a laser used to transfer data
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This is (or was) referred to as "Band 2 VHF"  The other VHF bands being used for purposes other than public broadcast. VHF being "very high frequency", higher than HF (= Short-wave) but lower than UHF (Ultra high frequency, as used for example by normal television transmission) \nIf by "Why?", you mean "Why was this frequency selected for this purpose?" I have no expert knowledge, but presume it was a useful trade-off between the bandwidth required for FM audio transmission, and the area a transmitter could cover effectively.