The word RMS stands for Root Mean Square. The power of the RMS is defined as the square root of a square that means the instantaneous values of an electric power signal. RMS is also known as quadratic mean. The strength of the RMS can also be explained by the continuous power varied according to the squares of rapid values during the cycle.

The value of the RMS is very important in the case of an AC signal. Because the fastest amount of AC signal varies continuously with time. Unlike the DC signal, which is permanent. Therefore, the immediate amount of electrical energy cannot be used directly in the calculation.

RMS power is also known as equivalent DC power because the RMS value gives the amount of AC power drawn by the bond as the power generated by the DC source.

For example, take a 5Ω load connected to a 10V DC source. In the case of a DC source, the amount of electrical energy remains present throughout the period. Therefore, the gravitational force is easily calculated, and is 20W.

But instead of a DC source, we use an AC source. In this case, the amount of electrical energy varies with time, as shown in the figure below.

The AC signal is a sinusoidal wave signal in most cases, as shown in the figure above. Since in a sinusoidal wave signal the interval value varies, we cannot use a quick value to calculate the force.

But if we find the RMS signal value above, we can use it to gain power. Suppose the RMS value is 10Vrms. Power dissipation per load is 20W.

The energy we get at home is the power of the RMS. Multimeters also provide an RMS value of AC power. And in the power system, we use system power which is also a valuable RMS.