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Yet, before the experiments of Stanciu and Hansteen, all-optical controllable magnetization reversal in a stable magnetic state was considered impossible. [ 1 ] In quantum field theory and quantum chemistry the effect where the angular momentum associated to the circular motion of the photons induces an angular momentum in the electrons is ...
The wire now exhibits a very large magnetic hysteresis: If a magnet is brought near the wire, the high coercivity outer shell excludes the magnetic field from the inner soft core until the magnetic threshold is reached, whereupon the entire wire — both the outer shell and inner core — rapidly switches magnetisation polarity. This switchover ...
A schematic representation of long distance electric power transmission. From left to right: G=generator, U=step-up transformer, V=voltage at beginning of transmission line, Pt=power entering transmission line, I=current in wires, R=total resistance in wires, Pw=power lost in transmission line, Pe=power reaching the end of the transmission line, D=step-down transformer, C=consumers.
The Earth's magnetic field has alternated between periods of normal polarity, in which the predominant direction of the field was the same as the present direction, and reverse polarity, in which it was the opposite. These periods are called chrons. Reversal occurrences are statistically random.
The Induced current is the current generated in a wire due to change in magnetic flux. An example of the induced current is the current produced in the generator which involves rapidly rotating a coil of wire in a magnetic field. It is a qualitative law that specifies the direction of induced current, but states nothing about its magnitude.
The greater the number of turns of wire, the stronger the field produced. Conversely, a changing external magnetic flux induces a voltage in a conductor such as a wire, due to Faraday's law of induction. [3] [4] The induced voltage can be increased by winding the wire into a coil because the field lines intersect the circuit multiple times. [3]
The electrical current is used to either create an opposing magnetic field, or to charge a field, which can then be repelled. When a current flows through a conductor in a magnetic field, an electromagnetic force known as a Lorentz force, pushes the conductor in a direction perpendicular to the conductor and the magnetic field. This repulsing ...
When a magnetic field along the axis is turned on (B points directly out of the screen), the Lorentz force drives a circular component of current, and the resistance between the inner and outer rims goes up. This increase in resistance due to the magnetic field is called magnetoresistance.