RMS value of a Square Wave. Find the rms value of a squarewave current that jumps back and forth from 0 to 2 A as shown below:
We need to find the square root of the average value of the square of the current. The waveform for current squared is (Figure 1)
The average value of current squared is 2 by inspection (half the time it is zero, half the time it is 4):
I_{rms} = \sqrt{\left(i^{2}\right)_{avg}} = \sqrt{2} A