The root mean square (RMS) value is used for alternating current quantities because it provides a value that relates the power of an AC signal to what it would be if the same power was delivered by a DC signal through the same resistor over the same time period. The RMS value is calculated by squaring the instantaneous values of a sinusoidal waveform at different points, taking the average of the squared values, and then taking the square root of the average. This RMS value represents the equivalent DC voltage or current that would produce the same heating effect as the AC signal.

1. Why Root Mean Square Value is
Used for Alternating Current
quantities?

2. DC Vs AC

3. Alternating Current

4. Average Value of Sinusoidal Waveform

5. Why RMS Value > Average Value
1. Square at different instants
2. Find Average by dividing
with no. of instants
3. Take the square root

6. RMS Value of Sinusoidal Waveform
(339V)

7. RMS Value of AC Vs DC Signal

8. The RMS value of alternating current
(AC) would produce the same heat as
that produced by direct current (DC)
when passed through the same resistor
for the same time
RMS Value of AC Vs DC Signal

9. Instrumentation