Physics of Microwaves
Microwaves are used in our everyday lives but most most people don't realize that physics plays a large and important part in the simple household item. Whenever we heat our food we are oblivious to the forces that cause such a thing to occur and we don't fully understand what happens in front of our eyes and how our food really gets heated in such a simple and efficient way.
The first thing people need to understand is that microwaves are actually electromagnetic waves. Wavelengths and frequencies range from 300 MHz up to 300 GHz but, the average microwaves at home or restaurants operate at frequencies of about 2.45 GHz. Microwaves consist of a waveguide, magnetron, fan, power supply and a turntable with the base plate. These items help create the magical ability to heat our food and each have a different purpose. Magnetrons are the ones that create the waves and feeds the waveguide into the cooking chamber. Most microwaves are created in a cuboid shape and creates a chamber where it has metallic walls and so it acts like a Faraday cage which is an enclosure created by conducting material. Metal grids also cover the front door, which is made of glass, and the the light bulb cavity. Rotating turntables are also found in almost all microwaves and this helps them ensure that the food is all evenly heated.
To achieve the best possible way to heat up your meals, the microwave does not use solid state devices. Instead, electron beams from tubes under the combined effect of the electric and magnetic fields that are made to curve and follow trajectories. Magnetrons are also mostly used in microwave ovens and it has changed everything. In 1921 it was first discovered and put into use and as the years continue...
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...owaves actually reflect off of the metal. This can be especially bad if you have a metal container, with that the food won't be able to heat up because the metal is reflecting all the microwaves and leaving the food cold. The bigger issue with this is that there is a possibility that the microwaves can be knocked back to the magnetron which can lead to permanent damage to it.
With some downsides to using a microwave there aren't any drastic ones that will lead you to stop using it. The microwave has become a staple for every American home and it allows people to feed their family on a daily basis and all thanks to physics it helps feed over millions of people in the United States. Now that you have gained all this knowledge maybe you will hopefully enjoy physics more and think about how it affects your microwave every time you decide heat your cold pizza up.
Furthermore, AMR should be recognized as the combined solid -fluid system, whereby, in essence, a temperature gradient is established throughout the AMR and a fluid is used to transfer heat from the cold end to the hot. This subtle but important idea produced a new magnetic cycle distinct from Carnot, Ericsson, Brayton, or Stirling [6].
Electromagnetic waves are waves that can propagate even though there is no medium. A magnetic field that changes with time can generate an electric field that also changes with time, and an electric field that changes with time can also produce a magnetic field. If the process is continuous it will produce a magnetic field and electric field continuously. If these magnetic fields and electric fields simultaneously propagate (spread) in space in all directions then this is a symptom of the wave. Such a wave is called an electromagnetic wave because it consists of an electric field and a magnetic field that travels in space.
During the late 1970's, the world of diagnostic imaging changed drastically due to the introduction of Magnetic Resonance Imaging, also known as MRI. For over 30 years, they have grown to become one of the most significant imaging modalities found in the hospitals and clinics ("EDUCATIONAL OBJECTIVES AND FACULTY INFORMATION"). During its ancient days, these machines were referred to as NMRI machines or, “Nuclear Magnetic Resonance Imaging.” The term “nuclear” comes from the fact that the machine has the capability of imaging an atom's nucleus. Eventually, the term was dropped and replaced with just MRI, because “nuclear” did not sit well with the public view ("EDUCATIONAL OBJECTIVES AND FACULTY INFORMATION"). Many people interpreted the machine to produce an excess amount of radiation in comparison to the traditional X-ray machine. What many of them were unaware of, MRI does not disperse a single ounce of ionizing radiation making it one of the safest diagnostic imaging machine available to this date. MRI machines actually use strong magnetic fields and radio waves to produce high quality images consisting of precise details that cannot be seen on CT (Computed Tomography) or X-ray. The MRI magnet is capable of fabricating large and stable magnetic fields making it the most important and biggest component of MRI. The magnet in an MRI machine is measured on a unit called Tesla. While regular magnets commonly use a unit called gauss (1 Tesla = 10,000 gauss). Compared to Earth's magnetic field (0.5 gauss), the magnet in MRI is about 0.5 to 3.0 tesla range meaning it is immensely strong. The powerful magnetic fields of the machine has the ability to pull on any iron-containing objects and may cause them to abruptly move with great for...
MRI was originally known as Nuclear Medical Resonance (NMR) (Siemens, , it was designed and used for chemical and physical molecular analysis. The magnetic resonance phenomenon was discovered by Felix Bloch and Edward Purcell, who have worked independently in 1946; their work was rewarded with the Nobel Prize in 1952 (Dr. J. Hornak, n.d).
MTC ONLINE, " Reports of Current Experimentation with Microwave and EM Weapons," <http://www.heart7.net/mcf/1.html> (10 August 2003)
The dangers of the electromagnetic can be low on danger and high on danger. Depending on the amount of how much the body absorbs verifies the lethality of the EMFs.
Customers who have tried other hot dog cookers talk about how extremely satisfied they are when the hot dog cooker cooked at a fast rate and was able to cook several hot dogs in a short amount of time. Customers who did not encounter any manufacturing problems or technical errors on this exact device praised the cooker for being a significantly better alternative to cooking hot dogs in a microwave, stove, or grill. According to reviews, the main advantage of this product is how quickly it prepares hot dogs, far superior to grills and stoves, and while microwaves can rival their speed, they sacrifice hot dog quality to do so. Customers also loved the simplistic design of it and because of its easy usage and cheap price tag, and thus, when it works, this product was praised on several accounts. There were several issues with this product, however.
Some materials are paramagnetic. This is the case when the orbital and spin motions of the electrons in a material do not fully cancel each other, so that the individual atoms act like magnetic dipoles.
Though people may think that they do not experience heat radiation that often, they may be surprised when hearing that microwaves work by the use of radiation heat. Microwaves work to disturb certain water molecules that are found in foods that atomically generate heat by circulating inside of a confined space (“Dan Berger's Pages at Bluffton University”). That heat then accumulates within the item inside the microwave due to the radio waves that occur in the device. So, whenever one is in use of a microwave, they are transmitting heat that sparked the atoms located inside of food, by the use radio
The way electromagnetic radation interacts with matter can be detected with different sensors. How the radation interacts depends upon the properties of the medium, the wavelength of the incedent radation and the incident angle. There are four major types of interactions that occur: transmission, reflection, scattering and absorption (Lillesand and Kiefer, 1994).
Magnets are stones that produce magnetic fields. The magnetic field is invisible, but is responsible for the most noticeable aspect of a magnet: the attraction of a metal object or the repulsion of another magnet. Magnets are used in common everyday household items: credit cards, TVs, speakers, motors, and compasses. A magnets strength is measured by its magnetic moment. (“Magnetism”)
The microwave is a prime example of technology making us happy. If we were to get rid of the microwave, many people would be angry because it is a very helpful and time saving device. If there was no microwave people would not be able to defrost the ground meat they forgot to leave out, nor would they be able to cook a hot pocket for lunch when they were short on time. Some people believe that items that are efficient make society happy.
All university students know the convenience and importance of the microwave. The microwave is particularly important for students living in the Towers, as this is their only kitchen appliance. Since microwaves are a staple for university students, they become dirty quickly. The best way to keep microwaves clean is to clean up spills immediately. If you can 't, however, do this, follow the steps below. Your microwave will be spotless again almost instantly.
In fact, everything that works around you makes use of the magnetic field. Although you cannot see it, you can be aware of it if you observe your surroundings. Magnets can be found in the simplest or the most complex devices you employ every day. From your home appliances like refrigerator, microwave oven and electric fan, to your business office equipment like computers and printers—all of these devices make use of magnets.