In certain applications, electromagnets are better than permanent magnets because:
(more than one answers can be correct)
The strength of the magnetic field of an electromagnet can be controlled.
The polarity of an electromagnet can be reversed.
Electromagnets can be made to act as a magnet when needed.
An electromagnet is a temporary magnet. Its magnetism is only for the duration for which the current is passed through it. So, the magnetism of an electromagnet can be switched on or off as desired. An electromagnet is better than permanent magnet because it can produce very strong magnetic field and its strength can be controlled by varying the number of turns in its coil or by changing the current flowing through the coil. Its polarity can also be changed by changing the direction of electric current in the coil.