Poles of magnet

Electromagnet 

When the current carrying coil is brought near a suspended bar magnet one side of the coil repels the north pole of the magnet. The otherside of the coil attract the north pole of the magnet. Thus, a current carrying coil has both north and a south pole like a magnet. Such a magnet is called electromagnet.

Factors which effect the strength of electromagnet : 
(A) magnetic effect of current depends on number of turns.    
(B) magnetic effect of current depends the value of current.    
(C) magnetic effect of current depends on the nature of core inside the coil.

Uses of electromagnets 
(i)    They are used to lift heavy iron pieces. They are fitted on cranes lifting heavy objects of scrap iron.
(ii)    They are used in many devices like electric bell, electric horn, telephone receiver, electric relay, microphones, radio set, television, loudspeakers etc.
(iii)    The electromagnets are also used to separate magnetic material from the junk.
(iv)    Doctors use tiny electromagnets to take out small pieces of magnetic material that have fallen in the eye.