Connect a wire of the dormitory electric fan privately. When the appliance is plugged in, it will ring. What is the reason? Is it harmful to electrical appliances?
There are many factors, such as weak connection of wire ends, poor contact between plug and plug, insufficient voltage, and electrical appliances themselves. It is also possible that the magnetic field in the electric fan affects the wires, which is what he calls electromagnetic induction. There must be a little impact on electrical appliances, but it won't be serious.