A microwave oven is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. American engineer Percy Spencer is generally credited with inventing the modern microwave oven after World War II. Microwave ovens are a common kitchen appliance and are popular for reheating previously cooked foods and cooking a variety of foods.
About Microwave oven in brief
A microwave oven is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. American engineer Percy Spencer is generally credited with inventing the modern microwave oven after World War II from radar technology developed during the war. Microwave ovens are a common kitchen appliance and are popular for reheating previously cooked foods and cooking a variety of foods. They rapidly heat foods which can easily burn or turn lumpy if cooked in conventional pans, such as hot butter, fats, chocolate or porridge. After microwave ovens became affordable for residential use in the late 1970s, their use spread into commercial and residential kitchens around the world. They usually do not directly brown or caramelize food, since they rarely attain the necessary temperature to produce Maillard reactions. Exceptions occur in cases where the oven is used to heat frying-oil and other oily items, which attain far higher temperatures than that of boiling water. The exploitation of high-frequency radio waves for heating substances was made possible by the development of vacuum tube radio transmitters around 1920. By 1930 the application of short waves to heat human tissue had developed into the medical therapy of diathermy. The invention of the cavity magnetron made possible the production of electromagnetic waves of a small enough wavelength. The magnetron was a crucial component in the. development of short wavelength radar during World War I and II. In 1937, a multi-cavity magnetron built by FRSE was built for British and American military radar installations.
An early 6W version, built by General Electric Company, was given to the U.S. General Electric Research Laboratories in late September 1940 to offer their financial and industrial customers in exchange for their financial support. In late 1940, a working prototype of a 6W microwave oven was built by the General Electric S.W. S.E. Research Laboratories, London. They invented a valve that could produce pulses of microwave energy at a wavelength of 10 cm of radio wavelength. The oven was first sold in 1946. Sharp Corporation introduced the first microwave oven with a turntable between 1964 and 1966. The countertop microwave oven, introduced in 1967 by the Amana Corporation, was introduced in 1969. It is still too large and expensive for general home use. However, such high heat sources can be added to microwave ovenS, in the form of a convection microwave. The primary heating effect of all types of electromagnetic fields at both radio and microwave frequencies occurs via the dielectric heating effect, as polarized molecules are affected by a rapidly alternating electric field. This patent proposed radio frequency heating, at 10 to 20 megahertz. Heating from microwaves that have a wavelength that is small relative to the cavity is due tofar-field effects that are due to classical electromagnetic radiation that describes freely propagating light and microwaves suitably far from their source. The microwave oven can be used for heating in many industrial processes such as the manufacture of plastics and paper.