How does the microwave oven heat up?

How does the microwave oven heat up?

Magnetrons are used in household microwave ovens, which convert electrical energy into microwave energy. There are two types of magnetrons: pulsed magnetrons and continuous magnetrons. The continuous wave magnetron is used in the microwave oven. The propagation speed of microwave is close to the speed of light, and it can be reflected and refracted during the propagation process. It has three important characteristics related to heating. When microwaves encounter metal objects, such as silver, copper, aluminum, etc., they will be reflected like a mirror reflecting visible light.

Therefore, metal is often used to isolate microwaves. Metal is commonly used in microwave ovens to make cabinets and waveguides, and metal mesh and tempered glass are used to make furnace door observation windows. When microwaves encounter insulating materials, such as glass, plastics, ceramics, mica, etc., they will pass through as smoothly as light passes through glass. Therefore, insulating materials are often used to make dishes without affecting the heating effect. When microwave encounters water or fat-containing food, it can be absorbed in a large amount and converted into heat energy. The microwave oven uses this feature to heat food.