Ever wondered how microwaves heat up food so quickly and efficiently? These appliances contain a part called a magnetron, which uses electricity to create high-powered radio waves. The waves are pushed into the microwave’s interior, where they bounce off the metal walls and penetrate whatever food you’re cooking. The turntable spins to help the waves hit the food from all angles, and this process makes the molecules in the food vibrate, warming them up. However, one of the downsides of microwave cooking is that radio waves can only travel a few centimeters into your food, so larger items don’t always cook evenly.
Water and other homogeneous liquids can superheat[54][55] when heated in a microwave oven in a container with a smooth surface. That is, the liquid reaches a temperature slightly above its normal boiling point without bubbles of vapour forming inside the liquid. The boiling process can start explosively when the liquid is disturbed, such as when the user takes hold of the container to remove it from the oven or while adding solid ingredients such as powdered creamer or sugar. This can result in spontaneous boiling (nucleation) which may be violent enough to eject the boiling liquid from the container and cause severe scalding.[56]
We wanted to find microwaves that could cook a variety of foods, including frozen meals, popcorn, and whole potatoes, quickly and evenly. Some models have functions that cook food using preprogrammed time and power level settings. Others use built-in sensors that automatically adjust the cooking time based on the amount of steam emanating from the food. But regardless of the technology used, none of the microwaves we tested were perfect. Some microwaves had a more accurate baked-potato setting, while others were better at defrosting ground beef. We’d recommend choosing a microwave that excels at cooking the food you plan to prepare most often.
We wanted to find microwaves that could cook a variety of foods, including frozen meals, popcorn, and whole potatoes, quickly and evenly. Some models have functions that cook food using preprogrammed time and power level settings. Others use built-in sensors that automatically adjust the cooking time based on the amount of steam emanating from the food. But regardless of the technology used, none of the microwaves we tested were perfect. Some microwaves had a more accurate baked-potato setting, while others were better at defrosting ground beef. We’d recommend choosing a microwave that excels at cooking the food you plan to prepare most often.
The GE JES2051SNSS was one of the best models we tested at defrosting frozen meat. But at 19.25 by 13.63 by 23.88 inches, we felt it was just too large for most kitchens. Our own experience and user feedback taught us that a smaller microwave is preferable. However, we think this is an excellent choice for someone who has ample counter space and prefers a larger microwave.
All microwaves use this same core technology, but today, there are many models available that come with a variety of additional features. For instance, many products have pre-programmed settings to cook common foods, as well as various cooking methods, such as steaming and grilling. Depending on what size and features you want, you can spend anywhere from $20 to $2,000 on a new microwave. 
There are, however, a few cases where people have been exposed to direct microwave radiation, either from appliance malfunction or deliberate action.[67][68] The general effect of this exposure will be physical burns to the body, as human tissue, particularly the outer fat and muscle layers, has similar composition to some foods that are typically cooked in microwave ovens and so experiences similar dielectric heating effects when exposed to microwave electromagnetic radiation.
Any object containing pointed metal can create an electric arc (sparks) when microwaved. This includes cutlery, crumpled aluminium foil (though some foil used in microwaves is safe, see below), twist-ties containing metal wire, the metal wire carry-handles in paper Chinese take-out food containers, or almost any metal formed into a poorly conductive foil or thin wire, or into a pointed shape.[57] Forks are a good example: the tines of the fork respond to the electric field by producing high concentrations of electric charge at the tips. This has the effect of exceeding the dielectric breakdown of air, about 3 megavolts per meter (3×106 V/m). The air forms a conductive plasma, which is visible as a spark. The plasma and the tines may then form a conductive loop, which may be a more effective antenna, resulting in a longer lived spark. When dielectric breakdown occurs in air, some ozone and nitrogen oxides are formed, both of which are unhealthy in large quantities.
There are two types of microwave vent systems: recirculating and external. Recirculating vents simply pull the air up into the appliance, run it through a filter to remove impurities, then push it back out into your kitchen. This type of ventilation system is ductless and easier to install, but it doesn’t perform as efficiently as external ventilation. 
A microwave oven (commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range.[1] This induces polar molecules in the food to rotate and produce thermal energy in a process known as dielectric heating. Microwave ovens heat foods quickly and efficiently because excitation is fairly uniform in the outer 25–38 mm (1–1.5 inches) of a homogeneous, high water content food item.
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