INTRODUCTION:

It is a field that exerts forces (called magnetic) on materials. As the electric field is also a vector field, but that does not produce any effect on charges at rest (as it does the electric field where it accelerates through electric force). However, the magnetic field influences moving electric charges. If a moving charge passes through a magnetic field, it undergoes the action of a force (called magnetic force). This force does not modify the speed module but the trajectory (see magnetic force). A magnetic force appears on a conductor through which electricity circulates and which is in a field. The magnetic field is present in the magnets. On the other hand, an electric current also generates a magnetic field. https://steemitimages.com/0x0/https://i.ytimg.com/vi/Wsdo-8USdvg/maxresdefault.jpg [Source](https://steemitimages.com/0x0/https://i.ytimg.com/vi/Wsdo-8USdvg/maxresdefault.jpg) MAGNETIC FIELD A magnetic field is a force field created as a result of the movement of electric charges (flow of electricity). A magnetic bar or a cable that carries current can influence other magnetic materials without touching them physically because the magnetic objects produce a "magnetic field". Magnetic fields are usually represented by "magnetic field lines" or "lines of force". At any point, the direction of the magnetic field is equal to the direction of the lines of force, and the field strength is inversely proportional to the space between the lines. In the case of a magnetized bar, the lines of force leave one end and curve to reach the other end; these lines can be considered as closed loops, with one pole of the loop inside the magnet and another outside. At the ends of the magnet, where the lines of force are closest, the magnetic field is more intense; on the sides of the magnet, where the lines of force are further apart, the magnetic field is weaker. According to its shape and its magnetic force, the different types of magnet produce different patterns of lines of force. https://steemitimages.com/0x0/https://i.ytimg.com/vi/TEJMIdIfnhk/hqdefault.jpg [Source](https://steemitimages.com/0x0/https://i.ytimg.com/vi/TEJMIdIfnhk/hqdefault.jpg) The structure of the lines of force created by a magnet or by any object that generates a magnetic field can be visualized using a steel file or iron filings. Magnets tend to be oriented following the magnetic field lines. Therefore, a compass, which is a small magnet that can rotate freely, will be oriented in the direction of the lines. By marking the direction that the compass points when placing it in different points around the source of the magnetic field, the power lines diagram can be deduced. Likewise, if iron filings are shaken on a sheet of paper or a plastic sheet above an object that creates a magnetic field, the filings are oriented along the lines of force and allow to visualize its structure. Magnetic fields influence magnetic materials and charged particles in motion. In general terms, when a charged particle moves through a magnetic field, it experiences a force that forms right angles to the velocity of the particle and to the direction of the field. Since the force is always perpendicular to the velocity, the particles move in curved trajectories. Magnetic fields are used to control the trajectories of charged particles in devices such as particle accelerators or mass spectrographs. MAGNETIC FIELD OF A MAGNET In the space surrounding a magnet there is a magnetic field, which is caused by the movement of electrons around the nuclei of atoms and by a rotating movement of electrons on themselves that is called spin. A magnet can rotate freely in a horizontal plane and is oriented approximately in the geographic North-South direction. In consequence, if a magnet in the aforementioned conditions is placed in a certain region of the space and changes position, orienting itself in another direction, this indicates that a force acts on the magnet and therefore an interaction has been carried out. It is said then that in the region of the space where the magnet is located there is a magnetic field. The direction of the magnetic field is the longitudinal axis of the magnet and the direction, which is directed from the South pole (S) North alpolo (N). https://steemitimages.com/0x0/http://3.bp.blogspot.com/-EVww_Fvznb0/VFFIbXB9JAI/AAAAAAAAGXg/WoCeJd_gmII/s1600/iman-campomagnt.gif [Source](https://steemitimages.com/0x0/http://3.bp.blogspot.com/-EVww_Fvznb0/VFFIbXB9JAI/AAAAAAAAGXg/WoCeJd_gmII/s1600/iman-campomagnt.gif) MAGNETIC FIELD OF A CURRENT EXPERIMENT OF OERSTED If a conductor circulates an electric current (moving charges) in the space surrounding the conductor, a magnetic field is created. Hans Christian Oersted discovered that an electric current influences the orientation of a compass needle. Oersted proved in 1820 the close link that exists between magnetism and electric current. He placed over a compass (magnetic needle) and parallel to it a straight wire whose ends are connected to a direct current source. If a switch S is inserted in the circuit, it is observed that while the circuit is open there is no defined movement of electric charges in the wire, so that the magnetic field does not exist and the magnetized needle maintains its original position. When the circuit is closed, there is a defined movement of electrical charges in the wire and a magnetic field is created around it. http://images.slideplayer.com/11/3320233/slides/slide_26.jpg [Source](http://images.slideplayer.com/11/3320233/slides/slide_26.jpg) MAGNETIC FIELD LINES The lines of force of a magnetic field are continuous lines that do not intersect each other. To represent and describe a magnetic field magnetic field line or induction lines are used. Like electric fields, magnetic fields can be materialized by force lines, which can have different forms, depending on the creative agent, of the field. Different shapes present the lines of force of the magnetic field created by a current, according to whether the conductor is rectilinear, circular or in the form of a coil. When it comes to the magnetic field created by a magnet the lines of forces leave an area of the same called north pin and return to another area that receives the name depolo sury is in the vicinity of these poles where the lines are tighter of forces and, as consequences, where magnetic phenomena manifest themselves most intensely. Notion of magnetic induction: The magnetic induction of a field, at a point of it, is the force acting on a unit of positive charge that moves, perpendicular to the lines of force, with a unit of velocity. It is represented by (). UNITS MAGNETIC INDUCTION OR MAGNETIC FIELD The magnetic induction unit in the InternationalSystem or MKS is calledTesla. In the cegesimal system or CGS, the induction unit is the Gauss. A Tesla is the induction of a magnetic field in which a charge of a coulomb that moves perpendicular to the lines of forces with a speed of 1 m / sec is subjected to a force of unnewton. There is a magnetic field when entering a region of space, a moving load experiences a force that depends on the speed of the load. http://slideplayer.com/4063404/13/images/5/The+magnetic+field+line.jpg [Source](http://slideplayer.com/4063404/13/images/5/The+magnetic+field+line.jpg) MAGNETIC FORCE ON A RECTIFINE CURRENT An electric current consists of a defined movement of electrical charges in a conductor. A magnetic field exerts a magnetic force on an isolated load in motion. Therefore, it is to be expected that a magnetic field exerts a magnetic force on a rectilinear conductor through which an electric current flows. The force exerted by a magnetic field on a rectilinear conductor located perpendicular to the lines of force is equal to the product that results from multiplying the magnetic induction by the length of the conductor and the intensity of the current. CONCLUSION The force of magnetism causes a material to point in the direction of magnetic force points. As it appears in the diagram on the left, the magnetic force is illustrated by lines that represent it. In the diagram, the force of the magnet points from the positive pole to the negative pole. As seen in this image, on one side of the magnet it is called a positive pole, on the opposite side, a negative pole; the magnetic force flows from the positive side or pole, towards the negative pole. This drawing shows how they work. The magnetic force causes the small pieces of iron to be aligned and point in the direction of the magnetic field. A compass, in which a needle of magnetic material is placed so that it is free, and can turn freely, will be forced to point towards the positive pole. In fact, the magnet of the north pole (positive) of the Earth is located, geographically, in its south pole. The compass needle points north, but if you place the compass needle near a magnet, it will always point away from the north (positive) pole of the magnet. This drawing shows exactly where the poles are, it also shows that, with the passage of time, the poles become inverted.

BIBLIOGRAPHIC REFERENCES : -https://es.wikipedia.org/wiki/Fuerza_magn%C3%A9tica -http://www.etitudela.com/Electrotecnia/principiosdelaelectricidad/tema1.3/contenidos/01d56994aa1057511.html -http://www.sc.ehu.es/sbweb/fisica/elecmagnet/campo_magnetico/varilla/varilla.html -Casaca A., Silva J. P., Magnetic forces acting on rigid current-carrying wires placed in a uniform magnetic field. The -Physics Teacher, Vol 42, March 2004, pp. 161-163 https://steemitimages.com/DQmS8eRjFRTdRGDpuhKChAhmuhv2tP33RXRspKJEmNUR5BQ/image.png [Source](https://steemitimages.com/DQmS8eRjFRTdRGDpuhKChAhmuhv2tP33RXRspKJEmNUR5BQ/image.png ) > "A science is all the more useful the more universally its productions can be understood; and, on the contrary, they will be less insofar as they are less communicable. "- Leonardo Da Vinci https://steemitimages.com/0x0/http://1.bp.blogspot.com/-fkYiJhY4xuc/UwBSqYSfCjI/AAAAAAAAB3I/aGUOw_0QTPA/s1600/eff_li06.gif https://steemit.com/steemstem/@borcast/amazing-how-is-electric-power-created Greetings, see you soon! @borcast