RMS Value of a voltage waveform consisting of a superimposition of 2V DC and a 4 V peak to peak square wave is?
Just a hint.



simulate this circuit &ndash; Schematic created using CircuitLab
Figure 1. Superimposing 4 V peak-to-peak squarewave on a 2 V DC signal will give a 4 V squarewave.
Now get the root of the mean of the squares. (This is easy because the duty cycle is 50%.)

The square of the voltage between 0 and T/2 is ...
The square of the voltage between T/2 and T is ...
The mean of those two squares is ...
The root of the mean is ...