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[4]: p.712 For example, if a positive charge is brought near the object (see picture of cylindrical electrode near electrostatic machine), the electrons in the metal will be attracted toward it and move to the side of the object facing it. When the electrons move out of an area, they leave an unbalanced positive charge due to the nuclei.
For example, the drum generator is based upon the figure to the bottom-right. A different implementation of this idea is the Faraday's disc , shown in simplified form on the right. In the Faraday's disc example, the disc is rotated in a uniform magnetic field perpendicular to the disc, causing a current to flow in the radial arm due to the ...
A real inductor's capacitive reactance rises with frequency, and at a certain frequency, the inductor will behave as a resonant circuit. Above this self-resonant frequency , the capacitive reactance is the dominant part of the inductor's impedance.
[8] Within two months, Faraday had found several other manifestations of electromagnetic induction. For example, he saw transient currents when he quickly slid a bar magnet in and out of a coil of wires, and he generated a steady current by rotating a copper disk near the bar magnet with a sliding electrical lead ("Faraday's disk").
Mutually coupled inductors can equivalently be represented by a T-circuit of inductors as shown. If the coupling is strong and the inductors are of unequal values then the series inductor on the step-down side may take on a negative value. [32] This can be analyzed as a two port network.
The mass of the rotor and the surface area of its vanes are analogous to inductance, and friction between its axle and the axle bearings corresponds to the resistance that accompanies any non-superconducting inductor. An alternative inductor model is simply a long pipe, perhaps coiled into a spiral for convenience.
For example, a nearby conductive surface will exert a drag force on a moving magnet that opposes its motion, due to eddy currents induced in the surface by the moving magnetic field. This effect is employed in eddy current brakes which are used to stop rotating power tools quickly when they are turned off.
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.