ACPhasors - Alternating Current and Phasors AC voltage from...

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Alternating Current and Phasors AC voltage from a wall outlet is a sinusoid with an amplitude of about 170 volts and a frequency of 60 hertz (377rad/s). The electrons are not actually traveling in a loop through the transmission lines, but instead are simply vibrating back and forth in the wire. The voltage in an outlet is normally given as 120V. This is the root-mean-squared voltage, a kind of average where the square r oot of the integrated m ean of the voltage s quared is taken. (A simple time average would be zero.) For sine waves, the RMS value is always V RMS =V max / 2 . In this case, 170/ 2 120 . A phasor is a mathematical construct similar to a vector. Using phasors to solve AC circuit problems is much easier than trying to process all the calculus and trigonometry involved with straightforward sinusoidal values and circuit-element behavior. A phasor consists of a magnitude and a phase angle that are both straightforward to determine. Suppose you are asked to convert a sinusoidal voltage like
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This note was uploaded on 04/05/2012 for the course PHYS 131 taught by Professor Tibbets during the Spring '11 term at Cuyamaca College.

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