Nature of Magnetic Field and Field Lines

We all play with magnets

When two magnets are brought close, they either attract or repel each other.

A magnet creates a field around it.

It attracts or repels another magnet that is brought into this field.

Let us learn more about Magnets

Magnets have two poles.

Unlike poles of magnets attract each other

While like poles of magnets repel each other.

Let’s discuss magnetic field

We know that magnet creates a field around it.

This field is shown using lines as above.

The field lines are directed from North pole to South pole from outside.

In the North pole, the field line is directed away from the magnet.

In the South pole, the field line is directed towards the magnet.

If the lines are closely arranged, then the strength of the field is more.

Therefore closeness of the lines represents the strength of the field.

When the same poles are brought within this field, they repel.

And when opposite poles are brought within this field, they attract.

Let us understand magnetic field lines with an experiment

Take a cardboard and spread it with iron fillings.

Now, place a bar magnet below the cardboard.

The iron fillings arrange themselves in the direction of field lines.

This experiment shows the field lines of the magnetic field around a magnet.

It also shows the penetrating power of the magnetic field.

Now let’s discuss an application of magnetic field

A metal detector works on the principle-based on magnetic field inducing current i.e. electromagnetic induction.

The pulsating current across the coil induces a magnetic field.

This magnetic field moves across the metal and generates an electric current in the metal.

The current induces a magnetic field which generates an opposite current in the coil that induces a signal indicating the presence of metal.

Revision

A magnet creates a field around it.

It has two poles namely, North pole and South pole.

The field is represented by field lines which are directed from north pole to south pole.

Any magnet or magnetic metal that is brought into the field attracts or repels the magnet.

The End