# rms value

Discussion in 'Electronics Homework Help' started by bhuvanesh, Feb 23, 2015.

1. ### bhuvanesh

201
0
Aug 29, 2013
i have learned what is rms value just before . its has been stated like"power dissipated with rms voltage is same power dissipated by equivalent dc voltage".i understand this point. Later question arose to me why we need rms value of signal and i accommodate myself that is to make analyses simple.

But i want strong answer why we are interested in Rms value.?

2. ### Harald KappModeratorModerator

10,370
2,264
Nov 17, 2011
The RMS value of an arbitrary signal tells you how much power an equivalent DC signal would deliver to a resistive load.

Look for example at the mains power coming from the outlet in your wall. To find out how much power this can deliver to e.g. a heater, a lamp etc., it is not very helpful to know that the voltage and current (for a resistive load) have a sinusoidal waveform and a peak value (although you could integrate V(t)*I(t) over a period of the sine wave). How much easier is it to know the RMS value of the voltage and calculate P=Vrms^2/R?

KrisBlueNZ likes this.
3. ### bhuvanesh

201
0
Aug 29, 2013
what you summing up is rms value make our work easy than integrating over period . Or is there anything more usefull that we can do with rms value of AC

4. ### Harald KappModeratorModerator

10,370
2,264
Nov 17, 2011
Isn't that enough and well worth having this value?

KrisBlueNZ and Arouse1973 like this.
5. ### bhuvanesh

201
0
Aug 29, 2013
course it is ,i am just making myself sure whether i am missing any other of it uses .Thank you