Why is rms root 2

Active Oldest Votes. It's example time: I think you didn't ask for the derivation of RMS Consider that both the bulbs are giving out equal-level of brightness. Improve this answer. Waffle's Crazy Peanut Waffle's Crazy Peanut 8, 7 7 gold badges 36 36 silver badges 74 74 bronze badges.

For example, 5 volts of DC would have the average value 5. But, 5 volts of AC is not 5. The average value is zero everytime. It's indeed RMS value. I understand it now. You're talking about the average value of half cycle not complete. Considering a complete cycle, it'd be definitely zero. In case of half cycle, the expression is the same as you said. By taking the square root, you get back to an unsquared value that averages the magnitudes, regardless of sign. Show 1 more comment.

This is what makes the rms value "a good idea". Alfred Centauri Alfred Centauri John Rennie John Rennie k gold badges silver badges bronze badges. Featured on Meta. Now live: A fully responsive profile. Through the magic of mathematics, there are imaginary numbers which are represented by the addition of an i to a number so that, for example, the square root of -2 is 1. Squaring 1.

This makes sense as the heating effect on a resistor is the same no matter which way the current is flowing. Finding the RMS voltage of a sinusoidal wave signal is easy because some pretty simple rules apply.

The RMS voltage of a sinusoidal is always the peak voltage divided by the square root of 2 1. Yes, this means that the peak voltage of volt RMS power is around volts and that the peak to peak maximum positive to maximum negative is volts. And guess what, divided by the square root of 2 is ! Most of us will never encounter the need to determine the RMS voltage of a waveform other than one that is sinusoidal.

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