Index
WHAT IS A MAGNETIC FIELD
A magnetic field is defined by the region of space where magnetic forces are present. Magnetic forces are forces that attract or repel metals. a region of space where magnetic forces exist, forces that attract or repel metals.
In general terms, the magnetic field can be defined as a non-visible field that exerts a magnetic force on objects that are sensitive to magnetism.
Objects that generate magnetic fields, such as magnets, have two poles, pole North (N) and South Pole (S). Magnetic poles can be found at the extremes of the field. If we have two different fields, their opposite poles will cause them to attract and their equal poles will cause the two fields to separate.. Not only magnets generate magnetic fields, but also, for example, magnet currents, as we will see below.
The way to represent the magnetic field and the direction of the forces is through the magnetic field lines. These lines of force determine the direction in which the magnetic force acts and the area that is attracted by the action of the magnetic field. The Earth also has a magnetic North Pole and a South Pole. They do not coincide exactly with the geographic North Pole and South Pole, since each year these poles undergo a deviation, but almost. It is thanks to this magnetic North Pole and South Pole that compasses work. This deviation is defined in the reading of maps for ship navigation. The earth's magnetic field protects us from solar radiation.
A good understanding of magnetic lines and magnetic fields is very important in order to be able to determine the operation of generators, motors and virtually all electrical machines.
MAGNETIC FIELD EXPERIMENTS
HOW A MAGNETIC FIELD IS GENERATED
There are 2 ways to generate a magnetic field:
- Magnets. A magnet is an element that in itself possesses magnetic properties. There are magnets natural as well as magnetite is a powerful natural magnet, it has the property of attracting all magnetic objects. Magnetic objects are those that are attracted to magnetite. There are also Permanent artificial magnetsare magnetic objects which, when rubbed with magnetite, become magnets,
- Temporary artificial magnetsThe magnetic field is produced only when an electric current flows through them. An example is the electromagnet. If an electric current is passed through the conductor, a magnetic field is generated around the wire coil.. This can be seen by placing a piece of metal (a point for example) near the coil. We will see how it is attracted by the electromagnet.
In conclusion, a magnet or an electric current is needed to create a magnetic field.
MATERIALS ATTRACTED BY MAGNETIC FIELDS
The ferromagnetic are strongly attracted by the magnets. These include nickel, iron and steel alloys among others. These metals are the most commonly used to make permanent magnets.
The paramagnetic are weakly attracted by a magnetic force. This force is a million times weaker than that which attracts ferromagnets. Paramagnetic metals are copper, aluminium and the transition elements.
In contrast to ferromagnetic and paramagnetic metals, the diamagnetic respond to magnets by inducing an opposing magnetic field. Examples of these are carbon graphite, gold, silver, lead and bismuth.