A microwave oven does not use infrared radiation for cooking. Instead, it utilizes microwaves, which are a form of electromagnetic radiation with longer wavelengths than infrared radiation.
Microwaves in the range of 300 MHz to 300 GHz are used in microwave ovens. These microwaves are produced by a magnetron—a specialized vacuum tube that generates high-frequency electromagnetic waves.
When you turn on a microwave oven and set the desired cooking time and power level, the magnetron emits microwaves into the oven cavity. These microwaves are then absorbed by the food you place inside.
The absorption of microwaves by food causes water molecules within the food to vibrate rapidly. This rapid vibration generates heat throughout the food, leading to cooking or heating. It is this heat generation through the absorption of microwaves by water molecules that cooks or reheats food in a microwave oven.
Infrared radiation, on the other hand, has longer wavelengths than microwaves and is commonly associated with heat. Infrared radiation is emitted by hot objects and is often used in cooking methods like grilling, broiling, or using an infrared oven. It is not directly involved in the operation of a microwave oven.