Magnets and electricity
Natural magnets (magnetic stone) have a magnetic field that affects certain materials, such as iron (magnetic materials) with a magnetic force and attracts them towards it. Electric charges also have an electric field that affects other electric charges with an electric force. If the electric charges move, they produce an electric current.
The relationship between electricity and magnetism was observed in 1820 AD, after the Danish scientist Hans Oersted discovered during an important experiment that the magnetic needle deviates if it approaches a wire carrying an electric current. After this discovery, he concluded that magnetic fields occur as a result of small currents caused by movement within the atoms of matter. .
Magnetic effect on electric current
Where there is an electric current (moving electric charges) there is a magnetic field, and also a magnetic field created by moving electric charges or by an alternating electric field (the electric current that changes with time) and affects only moving electric charges, and the magnetic field is characterized by the presence of imaginary lines around it called lines magnetic field, the direction of the line from which at any point denotes the direction of the magnetic field, which is the path taken by a hypothetical single free-moving north pole in the magnetic field; As the magnetic poles always appear in pairs, there is no single magnetic pole, while the different magnetic poles attract (north-south pole) and similar ones repel (north-north), and the same applies to electric charges; Different attract (positive-negative charge) and similar repel (positive-charge positive).
Oersted Law
Electric currents generate magnetic fields around them according to Oersted's law, whereby the passage of an electric current in a wire generates a magnetic field in the field surrounding this wire. Also, magnetic fields generate electric currents, as in the phenomenon of electromagnetic induction, which was discovered by the scientist Faraday by chance in 1831 AD. Moving a magnet changes the magnetic flux, which is the total number of magnetic field lines that penetrate a given area and is measured in the Weber unit; Which leads to the generation of an inductive current, which is defined as a current generated by the movement of a conductor in a magnetic field, and an inductive current can also be generated by moving an electric file around a magnet or by moving a magnet inside a file.
Laplace's law
There is a mutual effect between magnetic fields and electric currents, and this effect is explained by the Laplace law of electromagnetic forces. When an electric current passes a certain ohmic conductor (for example, an electric wire) and this conductor is immersed in a specific magnetic field; It moves or rotates under the influence of an electromagnetic force resulting from the electric current and the magnetic field together.
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