When a microwave oven is turned off, several things happen:
Power interruption: The power supply to the microwave's magnetron, which generates the microwaves, is cut off. This means that the production of microwaves stops immediately.
Cooling down: The internal components, especially the magnetron (the microwave-generating device), may continue to emit residual heat after the oven is turned off. Many microwave ovens have built-in cooling fans to help dissipate this heat and prevent the magnetron from overheating.
Standing waves: Microwaves in the oven can create standing waves while it's operating. When the microwave is turned off, these waves quickly disperse and lose their energy. This is why the microwave oven does not emit microwaves when it's not in use, and there's no danger of radiation leakage once it's turned off.
Internal light and display: The internal light, which illuminates the cooking chamber, and the digital display typically remain off when the microwave is not in use.
Timer and settings reset: The timer and any selected settings (e.g., power level, cooking time) are usually reset when the microwave is turned off. This means that the next time you use the microwave, you'll need to enter your desired settings again.
Overall, once you turn off a microwave oven, it stops producing microwaves, and there is no radiation emission. Modern microwave ovens are designed with safety features to ensure that the microwaves are contained within the cooking chamber while it's in operation and that they do not escape when the oven is turned off. This prevents any potential harm to users and ensures the safe use of the appliance.