(1) It is a temporary magnet- it ceases to exist as soon as the current passing through it is stopped.
It does not lose its magnetism so quickly, that is why it is called a permanent magnet.
(2) The polarity can be reversed readily by reversing the direction of the current.
The polarity of a permanent magnet cannot be reversed.
(3) The strength of the magnetic field produced by an electromagnet can be increased or decreased without bodily shifting the magnet, by adjusting the current.
The strength of the magnetic field produced by a permanent magnet at a given point can not be changed without bodily shifting the magnet.
(4) An electromagnet can produce intense magnetic fields.
A permanent magnet cannot produce a very strong magnetic field.
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