An electromagnet is a soft metal core made into a magnet by the passage of electric current through a coil surrounding it
The difference between a permanent magnet and an electro magnet is that a permanent magnet is made from a "hard" magnetic material that maintains its magnetism over long periods of time. The magnetism in an electromagnet is created by current running through a coil of insulated wire that is wound around a piece of "soft"magnetic material.
The idea that <span>Max Planck propose to help explain why a blackbody radiator did not give off light of increasingly high frequency as its temperature increased is that </span>C. Matter can absorb light only in certain specific amounts.
