For example! When the closed loop is closed vertically, the magnetic field is instantly turned on, and then the magnetic field is instantly removed (the magnetic induction intensity is unchanged), the induced current generated in the closed loop is the largest, that is, the greater the change rate of magnetic flux at standard temperature and pressure, the greater the induced current generated.
Similarly, when the computer is turned on and off, its magnetic flux changes the most, so it not only radiates, but also radiates the most! Don't think that turning off the power immediately will be all right, which is not only useless but also harmful to the computer!
Of course, this example seems difficult to understand, but you will understand it if you look closely.
Note: The example involves the knowledge in Elective 3-2 in the new curriculum standard of senior high school.
Or put it this way, when you turn on the computer and turn it off, the computer makes the loudest sound from the host and the monitor, which proves that when the current is switched on instantly, the computer starts to work instantly, which will make a large number of electrons move suddenly and quickly, generate a magnetic field and also produce radiation. You can also put your hand in front of the monitor to switch on and off the computer, and you will feel a kind of pressure, which is due to the effect that the emitted high-speed electrons hit your hand. So you can understand!
There is also radiation when the computer is working, but it is not as serious as turning it on or off. There will still be radiation for some time after the computer is turned off. It's no use turning off the power supply, because there is static electricity on the metal plate inside, so there will be weak radiation, which will really be gone after balance.
Television is as radioactive as refrigerator.