Microwaves work based on a technology called "microwave radiation" or "microwave heating." They do need to be turned on to work, as they require electricity to generate and emit microwaves.
Here's how microwaves work:
Generation of microwaves: Microwaves are electromagnetic waves with a frequency range between radio waves and infrared radiation. In a microwave oven, an electronic component called a magnetron generates these microwaves. The magnetron is responsible for converting electrical energy into electromagnetic radiation in the microwave frequency range.
Emittance of microwaves: Once the microwave oven is turned on and the cooking settings (time and power level) are selected, the magnetron emits microwaves into the cooking chamber.
Interaction with food: When you place food inside the microwave oven, the microwaves pass through the food. Microwaves have a special ability to penetrate certain substances, such as food, and they primarily interact with water molecules, fats, and sugars present in the food.
Dielectric heating: As the microwaves penetrate the food, they excite the water molecules, fats, and sugars, causing them to vibrate rapidly. This vibration generates heat due to friction between the molecules. The heat is produced throughout the food, cooking it from the inside out. This process is known as dielectric heating.
Cooking process: The cooking time and power level set on the microwave determine how long and how intense the microwaves will be emitted. Higher power levels emit more microwaves, leading to faster cooking. The microwave oven's control panel allows you to adjust these settings based on the specific cooking requirements.
Safety features: Modern microwave ovens are equipped with safety features such as interlocking switches on the door, which prevent the oven from operating when the door is open. This ensures that the microwaves stay confined within the oven during operation, preventing exposure to harmful radiation.
To summarize, microwaves work by emitting microwave radiation, which interacts with water molecules, fats, and sugars in the food to produce heat. They need to be turned on and set to the desired cooking settings to generate the microwaves and cook the food. Always follow safety guidelines and use microwave-safe containers when operating a microwave oven.