The purpose of the light inside microwaves serves two primary functions:
Illumination: The light inside the microwave illuminates the cooking area, allowing you to see the food as it cooks. This is especially helpful when you want to monitor the progress of your food or check for any spillages or splatters.
Safety: The light also acts as a safety feature. When you open the microwave door during or after cooking, the light comes on to signal that the microwave is still operating or that it's hot inside. This helps prevent accidental burns or injuries by providing a visual warning that the microwave is in use or recently used.
Now, regarding whether the light stays on when the microwave is unplugged and off, it depends on the specific microwave model. In some microwaves, the light turns off immediately when you unplug the appliance or switch it off. However, in certain models, there might be a delay before the light turns off completely. This delay can be due to residual electrical charge in the microwave's circuitry or a specific design feature of the microwave's control system.
To be sure about the behavior of the light in a specific microwave model, you should consult the user manual that comes with the appliance. The manual will provide accurate information on the light's operation and any specific details related to that particular microwave model.