microwave oven, device that uses microwaves microwave, electromagnetic wave having a frequency range from 1,000 megahertz (MHz) to 300,000 MHz, corresponding to a wavelength range from 300 mm (about 12 in.) to 1 mm (about 0.04 in.). Like light waves, microwaves travel essentially in straight lines.
..... Click the link for more information. to rapidly cook food. The microwaves cause water molecules in the food to vibrate, producing heat, which is distributed through the food by induction. A special electron tube electron tube, device consisting of a sealed enclosure in which electrons flow between electrodes separated either by a vacuum (in a vacuum tube) or by an ionized gas at low pressure (in a gas tube).
..... Click the link for more information. called a magnetron produces the microwaves. Typical output power for consumer devices ranges from 650 to 1200 watts. To ensure even heating, the magnetron directs its waves at a rotating metal disk with offset vanes, which scatters the waves through the oven cavity; a rotating platform for the food is sometimes used in addition. Power settings may reduce the amount of radiation by cycling a constant-output magnetron on and off for varying lengths of time, or may reduce the level of radiation constantly produced by an inverter magnetron. The magnetron may be supplemented by quartz and halogen bulbs for browning food, which microwaves do poorly.

microwave oven

Appliance that cooks food by means of high-frequency electromagnetic radiation. A microwave oven is a relatively small, boxlike oven that raises the temperature of food by subjecting it to a high-frequency electromagnetic field. The microwaves are absorbed by water, fats, sugars, and certain other molecules, whose resulting vibrations produce heat. The heating thus occurs inside the food, without warming the surrounding air. This process greatly reduces cooking time; baking and other tasks that may require an hour or more in a conventional oven can be completed in minutes in a microwave oven.

microwave oven [′mī·krə‚wāv ′əv·ən]

(engineering)

An oven that uses microwave heating for fast cooking of meat and other foods.