Root Mean Square A.K.A RMS value

Most of the utility supplies alternating current than direct current. This is because alternating current flow forward and backward and can supply current to a city. But Direct current won't do same as alternating current. So we need a equation to calculate using peak vloatge to determine the RMS value by varying DC current. Electrify people let do some calcutions on RMS value of alternating current.

The root mean square value of a quantity is the square root of the mean value of the squared values of the quantity taken over an interval. To understand further lets look at the sine waveform of alternating current.

The picture above shown is sine waveform of alternating current. VRMS represent as Voltage root mean sqaure. VPK is Voltage peak and VPP is Voltage peak to peak. Because alternating current flows forward and backward, the sin wave have positive value and negative value. In DC, the voltage will be constant because it flows in one direction. In that picture shows is 0.707 a is represent as amplitude. So based on this sine wave form the equation will be to get RMS value is Vrms= Vp/ √2

The reason the square have is, this is undistorted sine wave.So let's look one example to make you understand.In Malaysia 240V is the RMS value. So what is the Vp (voltage peak) ? To calculate the peak voltage is Vp = Vrms X √2 

Vp= 240V X √2
Vp = 340V
 

So 340V is the maximum peak voltage in the amplitude of the sine waveform. In Japan,USA has 120V and UK,Malaysia has 240V. This is called the RMS value for house distribute current.

 

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