What happens when the current in an electromagnet is turned on?

Answer 1

Many permanent magnets are based on iron compounds, so are conductive. Why they are magnets, the iron neuclei are individually magnetic and align through something called the Exchange interaction, which allows a closer approach of the nuclei than less comples inter atomic interactions. (just some properties of magnetic materials) The individual iron atoms group into regions called domains, these (in iron compounds) tend to also align, giving a reasonably good permanent magnetic nature for the bar of iron compound. So the individual; magnetic moment of the iron atoms are grouped into an overall alignment in the bar, leading to the permanent bar magnetic property. OK we have a (for example) rod if iron compound that is a bar magnet. If we put a current through it, it may play with the exchange interaction, disaligning the individual domains, reducing the overall magnetic flux intensity of the bar magnet. The current will develop an additional magnetic field which will spiral around the (assumed) length wise orientation of the bar magnet. This will create a superposition of the magnetic flux intensities, and likely work to disrupt the orientations of the magnetic domains within the barmagnet. So two effects, a possible change in the permanent magnetic flux intensity of the bar magnet and a generation of a secondary magnetic flux intensity which will be detectable as a spiral field around the metal object

Answer 2

The magnetic field of electromagnet is also reversed. If it was anti-clockwise first, then it will change to clockwise and vice versa.

Answer 3

The magnet field is come around the electromagnet and electromagnet start picking magmatic things.

Answer 4

Magnetism will reduce to some residual level of magnetism when current is reduced to zero. Residual magnetism could be zero, but not necessarily so.

Answer 5

It will spring into existence. That is, it will become an electromagnet.

Until current begins to flow around it, it's nothing but a hunk of metal.