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Q & A: RMS vs. peak

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Most recent answer: 07/29/2009
Q:
vrms=0.707 vp. from where we get the value 0.707???
- john (age 23)
canada
A:
For a nice sinusoidal wave, say Vpsin(ωt), the maximum voltage is Vp. The average square of sin(ωt) is just 1/2. (sin2 +cos2=1, and each has the same average.) So the average of the voltage squared is just Vp/sqrt(2). 1/sqrt(2) =0.707.

This only works for sine waves, not say triangle or square waves.

Mike W.

(published on 07/29/2009)

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