Yes, microwaves do experience a change in intensity from the moment they turn on until they reach their full power output. This change is due to the way microwave ovens work and how they modulate the energy sent out by the magnetron.
When you start a microwave oven, the magnetron, which is the device responsible for generating the microwaves, begins emitting microwave radiation. However, the energy output is not immediately at its maximum level. The magnetron typically starts in a low-power mode and gradually ramps up to its full power output over a short period of time, usually a fraction of a second to a few seconds, depending on the model.
The process of starting with low power and gradually increasing to full power is known as the "duty cycle." It is a method used to control the average power output of the microwave oven while maintaining a relatively constant power level during operation.
Once the microwave reaches its full power, it remains at that level until the cooking cycle is completed or until you manually adjust the power setting.
This duty cycle and gradual increase in power help prevent sudden energy spikes and ensure more consistent and controlled cooking. It also helps the microwave to avoid immediate stress and strain on its components when powered on, leading to a longer lifespan for the appliance.
In summary, microwaves do experience a change in intensity as they start and gradually reach their full power output, which is managed through a duty cycle to ensure smoother and more controlled operation.