Several loops of wire are wound using the holes made in a thick piece of paper.  The direction of the current is shown by the black arrows. When the current is going into the paper the magnetic lines are clockwise. Shown in red. When the current is coming up they are anti-clockwise. Shown in blue. It could be seen that the lines of force  clash in between the turns. Then they cancel and those areas become ‘null points’. Shown by the letter ‘n’. The forces join at the axis of the coil. This strong magnetic field is shown in green. If you insert a soft iron into the coil the strength of magnetism will increase as the lines prefer to pass through iron rather than through air.

Poles of the Electromagnet.

The side from which the lines emanate is the North pole and at the South pole the lines go in. There is a very easy way to find this.  It is called the Fleming's Right hand rule.

Fig.16. Fleming's right hand rule.

Grip the coil so that your fingers will point the direction of the current. Then the thumb will point the North pole. 

 Fig.17. Use the right hand rule to verify  the N and S poles.

Electric Bell

  The Electromagnet is shown in grey.  When the current passes it attracts the steel strip which acts as a spring. This is fixed at the base. Then the striker hits the bell. This will cut off the contact of the strip with the screw. As magnet does not get current the steel spring will pull the striker back This can hit can hit another bell. So on and so forth it will go on ringing as long as the current supply is there. 

Fig.18. Electric bell.

Fig.19. A barmagnet is dropped through a coil connected to  an ammeter or a voltmeter.  As the magnet falls the meter will indicate that an electric current has been generated.

Fig.20. Magnetism from Current A  few turns of a wire are wrapped round a direction finding compass. As a current passes through the wire  the pointer will move to one side depending on the direction of the current