# pattern of moving electrons in wire under AC

when we use a DC battery into a circuit the flow of electrons in wire creates a clear picture as they flow from negative terminal to positive terminal. under AC(Alternating current) we know how energy flows and what does it mean by $I_{rms}$ or average current etc. But what about the pattern in which electrons move?

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"The RMS value of a set of values (or a continuous-time waveform) is the square root of the arithmetic mean (average) of the squares of the original values"

Irms refers to the root mean square value of the current over time. This value is A/sqrt(2) if I(t) has the form A*sin(wt). Intuitively, if you look at a sin wave from 0 to pi, the amplitude seems to be average a little more than halfway from y = 0 to y = A.

To come to this result, you would sqare Asin(wt), take the average, and then take the square root, which would leave you with A/sqrt(2).

Current is always generated by very small, (approximately) continuous voltage drops in the wire. Think about tilting a rainstick one way or another. So when you are using AC, you are tilting the rainstick back and forth periodically, and electrons will get pushed back and forth in an (approximately) harmonic way.

Electrons will only move a short distance back and forth in the wire because of a drift velocity http://en.wikipedia.org/wiki/Drift_velocity which is very slow to the frequency of the AC current (says .00028 m/s in the wikipedia article, this depends on the wire and current you are using and is approximate)

Hope it helps

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