why do the magnets on a refrigerator door get hot.The ones that are used for the seal.?
349709
I would guess that the vibrations caused by the fridge's motor cause friction on the magnets holding the door closed.  The friction would heat the metal in the magnets like rubbing your hands together on a cold day.
415115
good question. refrigerators eject heat with work input. but heat pumps gives heat with work input.\n example. we use a normal refrigerators for cooling our food stuffs. but usually in cold countries they use a heat pump in the hall or in the bed room for heating up the room at the desired temperature to keep the room warm enough. both works on same principle but action are different.
519039
It really depends.  if you are trying to pass current through the magnet, hooking up the N pole to the + side of the battery, and the S pole to the - side of the battery, then nothing much, other than the magnet may heat up a bit.\n\nIf you are wrapping a copper coil around the magnet and then passing current through the coil, then depending on which way the current is flowing, and how strong a current you are using, you'll either make the magnet stronger, or make the magnet weaker.
1123749
Hey there:\n\nInteresting question, because a month ago, i stumbled upon a thrown away harddrive while walking my dog.  I desembled it while I was at home, and found inside it TWO EXTREMELY POWERFULL RARE EARTH MAGNETS.  Also, around on each side of these magnets, was a magnetic shield, that did not allow them to attract from one side, but yes from the other.  If I was you, look for any thrown away harddrive, they all have them, and you will also be getting an extremly powerfull magnet while you are at it.
905849
Microwave oven cannot operate with the door open, unless tampered with, and then they are dangerous to anyone around them.  Given that the magnetron is a sensitive component, and that it operates at high voltage, tempering with it can be deadly to whoever is doing it unless they know what they are doing (i.e. they are expert in the field, like electrical enginners or technicians)\nThe door prevents microwaves from going out because it contains a metallic mesh forming a Faraday cage with the rest of the metallic enclosure.  That means if you were to put a screen mesh on your ceiling -- a mesh with a pitch similar to that used in mircowave doors (visible in the window) or smaller, no microwave would be able to get through.\nMicrowaves are absorbed by stuff that contains water, which is how food gets warmed up.  If your ceiling is plaster, it contains water in fixed form; if it was heated with microwaves, it would start flaking off.  If there is no dammage at all, then you only are the victim of a sick joke and idle threat and you will not come to any harm.
15046
Insulation. The reason hot stuff gets cold and cold gets hot is that the temperature is dispersed among the area so that eventually an equilibrium is formed and the temperature is constant.  By creating a mini thermo area a flask provides no thermodynamic properties for the heat to disperse
116652
Because heat causes molecules to separate (expand). The metal lid has a lower liquifying temperature than the glass, and voila! It expands more than the glass, breaking the seal and opening more easily.
22759
A permanent magnet uses ferromagnetism, which - in laymen's terms - is caused by a huge number small electromagnets in the form of unpaired electrons orbiting an atom. In permanent magnets, these elementary magnets are mostly oriented the same way.\n\nBy heating the permanent magnet, the atoms are excited into vibrations which may change the orientation of the elementary magnets. Rather than acting in concert, the magnets become randomly aligned if the permanent magnet is heated long enough.\n\n\nStars and planets generate magnetic fields in a different way.
133407
It's because of evaporation.  Whenever something evaporates, it takes energy away from what it's touching, and the temperature goes down.
365976
It is a derivative of topuvfridge residual. What happens is a standard refrigerator takes all the thl drug elements from open food items within the fridge. This crude fermentation process is funneled out of the fridge and exhausted into the backside via a venting grill. The ions produced by the grill throw these toxins to the top of the fridge, where it forms a thin layer of dust. This dust can then be harvested and when mixed with ground up allergy pills, forms the hallucinogen "dust". Sometimes cats jump on top of a fridge and come down a raging beast. It is so powerful you have to use catnip to bring them down. This is why it is important to keep the top of the fridge clean.
71035
Not 100% sure. But I think its because the air inside isn't moving. The air inside is stationary, while it is continuously circulating outside, which causes changes in the temperature. IMHO
1150115
it depends on the alloy of stainless steel (there are MANY different varieties of stainless steel) -- some stainless steels are "magnetizeable," others are not.\n\ncommon non-magnetic stainless steels include those found in automotive exhaust systems and those found in naval submarine hulls.\n\nif you're talking about the outside case of the refrigerator, it's usually made of a magnetic steel (hence "refrigerator magnets")\n\nif your fridge's steel is non-magnetic, the only way to magnetize it is to replace the non-magnetic steel with a magnetic variety.  as an intellectual exercise, this is theoretically possible; however, it is not economically practical.
225345
All of them acts in cools the air in a household refrigerator, refrigerant gas (e,g Freon, ammonia,..etc) compressed through compressor and evaporated , and during that circle air cools and heat transfer occur.
385823
http://www.magnetsusa.com/magnets-shopping/category.php?id=109&name=Magnetic%20Door%20Hangers
920496
One theory of why a material, capable of being magnetised, becomes magnetic (i.e., attracts ferrous material), is that the individual, but randomly distributed 'domains' within are lined up (by some exterior force - e.g., magnetic field from a coil,  'stroking' with an already magnetised piece of iron/streel, etc.), so that the domains line up. The summation of their individual magnetic fields effectively produces one large magnetic field in  the material and makes what we call a magnet!   Some materials, after this process, retain their magnetism and are called permanent magnets, others, such as relay cores, once the external force is removed, exhibit very little residual magnetism.
194000
It's just like "positive and negative" for magnetism, isn't it?  People say them as though they mean something.  All they really mean is that there are two types of magnetic things--like ones repel, opposite ones attract.  We don't know why it's so, but we feel much better when we can attach a word to it.\n\nWe understand many things about gravity (as we do about magnetism), but we can't explain why it exists in the first place.  That question is not even in the scope of physics, really, because it can't possibly be confirmed or denied by any experiment.  But like many things, we want to believe that we understand it.
751183
A refrigerator (often called a "fridge" for short) is an appliance for the storage and preservation of perishable food; food kept in a refrigerator lasts longer than that left at room temperature as the cold inhibits bacterial growth. A refrigerator maintains a cold temperature above the freezing point of water; commonly refrigerators are used in conjunction with freezers, which maintain temperatures below freezing, or a refrigerator may have an integrated freezer compartment. The refrigerator is a relatively modern invention amongst kitchen appliances. It replaced the common icebox which had been a household item for almost a century and a half prior, and is sometimes still called by the name "icebox".\n\nCommercial units, which go by many other names, were in use for almost 40 years prior to the common home models. The fact that they operated with toxic ammonia gas systems made them unsafe for home use. Practical household refrigerators were introduced in the 1920s and gained wider acceptance in the 1930s as prices fell and non-toxic, nonflammable synthetic refrigerants, such as Freon or R-12 refrigerants were introduced.\n\nthe advantages and disadvantages u can look straight to my source... it has many information... i hope this helps... good luck ^^