Magnetic Fields: Properties and Laws
The Magnetic Field
The magnetic field is a region of space in which a point electric charge, value q, moving at a speed, suffers from a force that is perpendicular and proportional to the speed and the field, called magnetic induction or density magnetic flux.
Performance of Magnetic Field Lines
The performance of magnetic field lines can roughly estimate the magnetic field existing at a given point, taking into account the following characteristics:
- The magnetic field lines are always closed loops running north to south outside the magnet and from south to north within the magnet.
- Magnetic loops never intersect.
- The magnetic lines of different magnets attract and repel each other: The lines in the same direction attract the opposite direction and repel.
Biot-Savart Law
The infinitesimal magnetic flux density is used to calculate the total value of the magnetic field associated with an electric current flowing through a circuit from a simple addition operation infinitesimal element of current. Mathematically, this sum is expressed as an integral over the entire circuit C, so the magnetic flux density associated with a current is given by:
Ampere’s Law
Basically, Ampere’s law is used to calculate the magnetic fields of a certain course given to it by continual basis, relates an electrical current with the magnetic field it produces. It is used in drivers considered theoretically of infinite length, for example, to calculate the field around a straight conductor.
Faraday’s Law
Faraday observed that the intensity of the induced current is greater the faster the number of lines of force passing through the circuit changes. (In our case, the higher the velocity of the magnet or coil, the greater the amount of current is created in this last one.) This experimental fact is reflected in the law that states: The electromotive force e induced in a circuit is directly proportional to the speed with which the flux through the circuit changes.
Ferromagnetic Materials
Ferromagnetism is a physical phenomenon that occurs in the magnetic ordering of all the magnetic moments of a sample, in the same direction. A ferromagnetic material is one that can present ferromagnetism. The ferromagnetic interaction is the magnetic interaction that causes the magnetic moments to tend to be arranged in the same direction. It spreads throughout a solid to achieve ferromagnetism. Ferromagnetic materials are materials that can be permanently magnetized by the application of an external magnetic field. This external field can be either a natural magnet or an electromagnet. They are the main magnetic materials: iron, nickel, cobalt, and alloys of these.
Diamagnetic Materials
In electromagnetism, diamagnetism is a property of materials that is to be repelled by magnets. It is the opposite of ferromagnetic materials, which are attracted by magnets. The phenomenon of diamagnetism was discovered and nominated for the first time in September 1845 by Michael Faraday when he saw a piece of bismuth was repelled by either pole of a magnet, indicating that the external field of the magnet induces a magnetic dipole in the bismuth in the opposite direction. Diamagnetic materials are not attracted by magnets, are repelled, and do not become permanent magnets.