17 Facts About Alternating current


Alternating current is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction.

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Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, fans and electric lamps into a wall socket.

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Usual waveform of alternating current in most electric power circuits is a sine wave, whose positive half-period corresponds with positive direction of the current and vice versa.

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These types of alternating current carry information such as sound or images (video) sometimes carried by modulation of an AC carrier signal.

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Transmission with high voltage direct Alternating current was not feasible in the early days of electric power transmission, as there was then no economically viable way to step down the voltage of DC for end user applications such as lighting incandescent bulbs.

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Three Alternating current waveforms are produced that are equal in magnitude and 120° out of phase to each other.

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Bonding all non-Alternating current-carrying metal parts into one complete system ensures there is always a low electrical impedance path to ground sufficient to carry any fault Alternating current for as long as it takes for the system to clear the fault.

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The phenomenon of alternating current being pushed away from the center of the conductor is called skin effect, and a direct current does not exhibit this effect, since a direct current does not create electromagnetic waves.

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Since the Alternating current tends to flow in the periphery of conductors, the effective cross-section of the conductor is reduced.

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The Alternating current flowing on the surface of the inner conductor is equal and opposite to the Alternating current flowing on the inner surface of the outer tube.

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Waveguides have dimensions comparable to the wavelength of the alternating current to be transmitted, so they are feasible only at microwave frequencies.

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Alternating current is used to transmit information, as in the cases of telephone and cable television.

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The earliest recorded practical application of alternating current is by Guillaume Duchenne, inventor and developer of electrotherapy.

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Alternating current technology was developed further by the Hungarian Ganz Works company, and in the 1880s: Sebastian Ziani de Ferranti, Lucien Gaulard, and Galileo Ferraris.

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The direct Alternating current systems did not have these drawbacks, giving it significant advantages over early AC systems.

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In 1888, alternating current systems gained further viability with introduction of a functional AC motor, something these systems had lacked up till then.

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Notable contributors to the theoretical basis of alternating current calculations include Charles Steinmetz, Oliver Heaviside, and many others.

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