Microwave Definition and 346 Threads

For this lab, I'm supposed to use materials that heat up but doesn't allow heat to transfer. I've used raw spaghetti noodles already but I still a few more for more trials. So what materials are good for this lab? after heating up the material, I measure the distance between the "hot spots" so...

I want to power a device using microwaves. The microwave emitter will be about 1 meter away. I want the rectenna to be about a square meter in area and planar (not a dish). The rectenna will need to pass on about a kW of power. Is this possible? How do I design a rectenna like that? How much...

I'm doing a physics project on microwave ovens. I've been researching online and some sites say that you can place metal in microwave ovens because nothing will happen, and some say that you can't because metal reflects microwaves. I'm curious as to what the correct answer is and why. Thanks!

I have been working with a large number of triodes amplifiers in parallel pulesed by a large thyratron tube. Earlier, many of the triodes decided to arc and melt. The amplifier was huge and I need to replace it. I need a design for a microwave source that is small and more powerful (megawatts)...

Is this caused by a lack of nucleation for the gas pockets to be formed or the uneven heating of the water? A clean cup isn't proviingvery many nucleation sites and is it this combined with the even heating meanings the chance of the super heated molecules reaching these sites is reduced is...

Is the CMBR distinguished by a particular set of spectrometry signatures? If not, how is it differentiated?

CMB hot spots have a physical size that corresponds to the size of the horizon at age 300; 000 yrs. Assume one such hot spot region has been expanding together with the universe, how big in physical size (express in unit of light-year) has it become today? For this exercise, use a model of...

I have a Panasonic inverter, I understand it needs some sort of input to, CN701, three terminals numbered 1-2 & 3. On the diagram DPC-CN701 shows 2-3v on 1 & 3 & 0v on 2. Where can I get the sensors to control these points, I have been told that terminal 1 switches on the unit after...

As we know, the heating principle of microwave oven is by the vibration of water molecules inside the food. However, it is reminded that a cup of water should not be heated by the oven, otherwise, water would be overheating but not boils. Once it was stimulated, it boils. From the...

hi i would like to ask a question concerning the application of microwave beams. First: a microwave beam can be thought of as a laser beam but the light it emitts is in the frequency range of microwaves (see Maser)... I was wondering why such beams are not used for medical imaging...

Heres the question [PLAIN]http://img213.imageshack.us/img213/2669/16772870.jpg I know that I'm supposed to derive these values from the fact that I know the absorptions of 2 different isotopes of the diatomic molecule but I don't know how to go about doing it. I can obtain the masses of...

I thought I set the kitchen timer on it for a pizza in my oven, but turns out I had actually turned on the microwave, cooking nothing. It's really hot. I think I might have to throw it in the snow. Ran for ten minutes. Now it won't turn on at all. And it smells bad. Anything I should be worried...

I am a high school student and i am doing a science fair project about radiation. i have a microwave detector and i would like to know where i can find microwave length radiation so i can test and record results. I have tested microwaves and cell phones but i can't think of anything else. What...

Assume that a microwave oven operates at a frequency of 1.00 * 10^11 s^-1 a)what is the wavelength of this radiation in nm? my attempt: wavelength=c/v so 3.00 * 10 ^8/1.00 * 10^11 s^-1= 3 * 10^19m I would have to convert to nm correct? so 3 * 10^19 (1 * 10^-9)= 3 * 10^10 nm?? I know it's...

Homework Statement I am needing to check my results against Malus' Law --> [I = Iocos2(theta)] I am unsure how to get Io. So I have found my signal readings on the microwave detector and I know the angle that I rotated the microwave transmitter. I experimentally know the relationship...

Can Microwave radiation penetrates building materials? I'm living within 120 meters from a mobile phone base station and I'm concerned with possible health effects from it .

Hey, I am looking for information on the relationship between microwave wattage and standing waves. Does the wattage increase/decrease the size of the wave? Does wattage increase the frequency of the wave? I am also looking the relationship between the time a microwave is operating and...

I hope this is an appropriate forum for this question. What kind sort of impact might intensely blue shifted cosmic microwave background (CMB) photons have on hawking radiation? Could intensely blue shifted CMB photons drive a portion of newly created electrons and positrons into the even...

Hi, I am about to start making bulgarian yoghurt with unpaseurised gersey milk. The food forums say that the bacteria in the milk will compete with the yoghurt bacteria and so should be reduced (not necesserilly killed altogether) without destroying the enzimes and milk protiens. In...

I've read many stories of ants being inmune to microwave, and also of coakroches being very resistive to X-rays and heavy radiation. My first thought was that ants have little water content, but that doesn't sound right because most animal have plenty of water. So instead I maybe wondered that...

First of all I'm not sure this thread should be in this section or in the Thermodynamics one. I don't understand something. If I'm not wrong, the wavelength of photons used in microwave oven cooking is around 122 mm \sim 10^{-1} m, much greater than visible light photons (450 to 750...

Homework Statement Is there a diode in Tv / Microwave / Mobile ? if it is then for what purpose the diode is there ? Homework Equations I got an assignment to find the list of those projects in which diodes are used also mention the purpose of diodes in these projects , I've found 8...

I know there exist methods to store a microwave in a vacuum superconducting or dielectric chamber.From first sight it looks as promising energy storage device,more safe then a flywheel.Even if chamber will be broken microwave will just left and fly into space. Unfortunately,I was not able to...

Hello, I want to do a test heating a hot dog in a tube using a Magnetron from a 900W Microwave oven. Before doing the test I would like to know if there is any reasons not to mount the magnetron antenna on top of the metal tube, or on the side. (Please see attached picture) Also, will I...

So when you watch those youtube videos and they put a compact fluorescent light bulb in the microwave and it starts to glow , but how come we get visible light from something that we are shooting microwaves at , it seems like conservation of energy does not hold . but then when i was...

I remember seeing a physicist on TV putting an argon or nitrogen sealed glass tube in a microwave and when he turned it on the tube started flashing an emitting visible light, So how come when i put a sealed glass jar that i glued a lexan lid on in the microwave it does not emit light , i...

That explain cosmic microwave background ? Cosmic microwave background (referring to the hiss that was detected by Wilson and Penzias, using microwave wavelength satellites, and it is found everywhere) and it is evidence of the big bang, but is it evidence of anything else? Are there other...

Homework Statement Microwaves of wavelength 2.80 cm fall on a slit and the central maximum at a distance of 1.0 m from the slit is found to have a half-width (i. e. distance from middle of central maximum to first minimum) of 0.67 m. Find the width of the slit.

I read in a book that: Microwaves are considered lower in energy than infrared waves because they do not affect all molecules, only the polar ones. Polar molecules have slightly different electrical charges at their opposite ends, making them more responsive to microwave radiation than...

First I thought of posting this on the random thoughts thread, but I need an answer to this bugging question. Why the hell a microwave (the cooking device) makes that fanlike noise? While an infrared device (electric heater), visible light device (a flashlight), x-ray machine do not make any...

I am trying to come up with an explanation as to why this happened. My dad put a plastic container in the microwave with food in it. He microwaved it, and it turned out fine. He then took that one out of the microwave and put in another plastic container in. Also with food in it. The weird...

i am designing a stepped attenuator using pin diode as a switch in microwave office. i am having difficulty in using pin diode as a switch. i knw it is operate in forward bias and open in reverse bias. if i am giving a rf signal between 300 Mhz to 3 Ghz then how can i switch it to reverse bias...

I came across one article in Washington Post. It was talking about "microwave auditory effect," which I had no idea of. So, I have read the below regarding microwave auditory effect in wiki. http://en.wikipedia.org/wiki/Microwave_auditory_effect I still have no clue. Just jaw opening...

I have a microwave machine. I am questioning whether it has leakage or not. I am asking is there a way of measuring the leakage of microwave machine. What I have been doing was, I purchased oscilloscope, it is on the way. whenever I turned on the microwave machine, the following will be...

Microwave defrost :"Chaos" ? The defrost cycle on my microwave oven claims to use "Chaos". Can this be a serious Engineering idea or is it just a flahsy sounding term, meaning nothing?

If the light from a distant galaxy was red shifted far enough wouldn't it appear as microwave? Is it possible that the CMB is just more galaxies beyond what we consider to be the "observeable universe?"

HI there, I have a thought question. Normally when we wish to warm up food in a microwave oven, common sense tells us that the lid of the plastic containter (or container of whatever material) should be off, so that the microwave can reach the food. Just wondering...if the lid is on, ie...

Homework Statement Power microwave problem? A 1000W microwave oven heats 500 g of water from 10.0 degrees Celsius to 55.0 degrees C in a time of 2 min. the heat capacity of water is 4200 J/kgdegrees C Homework Equations have i done this properly? there are 4 other questions with...

Does anybody know any good manufacturers of microwave diodes? Specifically, I'm looking for rectification that can be operated at essentially as high of a frequency as I can get. This led me to look for Schottky diodes (anybody have a better suggestion?). So far, all the microwave...

Homework Statement I have a homework about microwave .I need to create a microwave ,a instrument can create a microwave, and I don't know how to do. I 'm form China ,so my English isn't good.And I hope you can help me !thanks! Homework Equations The Attempt at a Solution

Could some of the cosmic background radiation be produced within the fabric of space itself? What if the big bang was not a one of event 15billion years ago but is happening right now today, now, all around us within the quantum world? If indeed the CBr was occurring within the fabric of...

Does a microwave oven burns metallic objects? I never put spoons, forks, or aluminum foil inside a microwave because I'm afraid that the microwave oven will burn them. If I remember correctly, my brother put an aluminum foil inside and it burnt. Nonetheless, the interior of the microwave...

Homework Statement With a wavelength of 12cm, how do I show that the microwave frequency is approx. 2.5GHz? Homework Equations v=f x lambda The Attempt at a Solution I'm confused about the wave speed bit...

why does TEM waves have the same distribution of static fields in the transverse plane

i was dumbstruck :bugeye: after hearing the statement "that ice didn't melt when placed in microwave" from one of my friend, and its indeed true i checked by myself.And now I'm looking for the reason :)

Hi everyone: Have you ever heard anything about the effects of the microwave on body? ..

Hi, Can someone please give me some suggestions on how to use a microwave oven to determine the specific heat capacity of tap water? This is not a homework question, but an assignment and I have absolutely no idea how I can do this.This experiment will be done at home, so please no immersion...

Question> The fact (simplified) is that our planet is rotating arount the Sun, also our solar system is rotating... Is there available information on direction of CMBR in relation to our planet or to our solar system? THX foun answer myself Re: does the cosmos have direction...

I would like to put a cup of water in microwave and measure the temperature of the water as it rises with time in the microwave. Obviously electronic equipment will be fried in a microwave, but would it be possible to put a thermocouple in the water with its lead coming out of the microwave...

Metal inside a microwave oven --> ice? When I was younger, I placed water inside a tin pan and placed it inside a microwave. I tuned it on, sparks went everywhere and I quickly turned it off. I took the pan out and it was solid ice. How? A while ago I read an article in New Scientist that...