In the changing magnetic field, the induced current will make the conductor subject to ampere force. The direction of ampere will hinder the movement of conductor. This phenomenon is called electromagnetic damping. The phenomenon of electromagnetic damping originates from the principle of electromagnetic induction. The macroscopic phenomenon is that when the closed conductor and the magnetic pole move relative, electromagnetic resistance will be generated between them, which will hinder the relative movement. This phenomenon can be damper of drawer slides explained by Lenz's Law: when the closed conductor cuts the magnetic induction line with the magnetic pole, the closed conductor will produce induced current, or dynamic current, due to the change of the magnetic flux penetrated by the closed conductor. The magnetic field generated by this current will hinder the relative movement of the two. The resistance is proportional to the magnetic induction strength and relative velocity of the magnet. The drawer slide damper phenomenon of electromagnetic damping is widely used in occasions where the friction force and braking force need to be stabilized, such as watt hour meter, electromagnetic braking machinery, and even maglev train. Therefore, if the generator can be adjusted by the resistance, the generator can be adjusted.