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What do you mean by rms value of current and voltage?

Updated: 8/18/2019
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Pracas

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13y ago

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From Wikipedia:

"In mathematics, the root mean square (abbreviated RMS or rms), also known as the quadratic mean, is a statistical measure of the magnitude of a varying quantity. It is especially useful when variates are positive and negative, e.g., sinusoids."

Since AC voltage is a sinusoid, the RMS voltage is one measure of the amount of voltage. It is also measured as a peak-to-peak value. Since Current = Voltage divided by Resistance, the same RMS measurement approach applies.

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Q: What do you mean by rms value of current and voltage?
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What is rms value in ac system?

The r.m.s. value of an alternating current or voltage is the value of direct current or voltage which produces the same heating effect.


What is 10000 rms?

rms stands for root mean squared. rms voltage is a way of measuring a sort of average alterating current voltage as distinguished from peak-to-peak voltage. Likewise for ac rms current.


What is the conversion for rms voltage to mean voltage?

For an alternating voltage, the simple mean over a cycle would be zero. 'RMS' means 'root mean square', and is defined as the square root of the mean value of the square of the voltage, taken over a cycle. Thus whether the voltage is + or - , as it is in alternate half cycles, the value of its square is always positive, giving a real number for the square root. In fact the RMS value of voltage produces an RMS current which dissipates power at the same rate as a DC current of the same value. To find the RMS value of a sine wave with no DC offset, divide the peak value of the sine wave by square root of 2. **************************************************** Since the r.m.s. value of a sine wave is 1.414Vpk, and the mean voltage of a sine wave is 1.57Vpk, then, starting with the r.m.s. value: Vmean = (Vr.m.s. x 1.414) ÷ 1.57


Rms value of AC current is equal to main current at an angle?

The root-mean-square value is 0.707 times the peak value, for a sinusoidal voltage or current. Angle doesn't come into it.


Can you please explain what RMS value is?

RMS stands for Root Mean Square. It is a method of averaging where you take the squares of a bunch of samples, average them with an ordinary mean, and then take the square root. This gives greater weight to larger values. In the case of an ordinary sine wave, the RMS value is 0.707 times the peak value, 0.707 being 1/2 the square root of 2, and the peak value being one half the peak-to-peak value. For example, in the US, a "standard" 117VAC line voltage is actually an RMS voltage that corresponds to a peak voltage of 166VAC.RMS is a necessary unit because, often, the waveform is not sinusoidal, it is sawtooth, such as in a power supply. Using an ordinary VOM, calibrated for a sinusoidal AC scale in such a case, will give an inaccurate reading of ripple voltage. Most modern DMM's have a true-RMS mode which will work correctly by using sampling and analysis technology.RMS is also a necessary unit because RMS is a better indication of how much power a signal can impart to a load.Another answerRMS stands for Root Mean Square value.In electrical technology, where alternating current (AC) is used, RMS Voltage and RMS Current (Amps) must be used to calculate the average power supplied or consumed. See the link below on how to find the RMS.In fluid flow technology related to gases, velocity is calculated as an RMS value because it can be used to find the average velocity of an ideal gas.Yet Another AnswerBecause a AC current is continuously varying in both magnitude and direction, it's necessary to measure it in a meaningful way. The rms-value of an AC current is equivalent to the value of DC current necessary to do exactly the same amount of work. For example, a sinusoidal AC current which peaks at 100 A has an rms-value of 70.7 A, and does exactly the same amount of work as a DC current of 70.7 A.


What is the relationship between peak rms and average values of an ac voltage?

Peak voltage of an AC voltage is the value at its highest or lowest point.RMS (Root Mean Square) voltage of an AC voltage is a mathematical derivation involving the square root of the average value of the squares of samples of the voltage as the sample interval approaches zero.Average voltage is simply that - the average or mean voltage.For a true sine wave, RMS and average are equivalent, but they are not equivalent when the wave is distorted, or has some other shape such as triangular.RMS is the best way to measure an AC voltage, as it gives you a true reading of the amount of power that the voltage can deliver.One issue with non-RMS AC meters is that they typically measure the rectified, filtered peak value and then compensate by dividing by 1.4. This is not correct unless the voltage is a sine wave.AnswerThe peak value of an a.c. voltage or current is the amplitude of that voltage or current waveform -i.e. the maximum value of voltage or current in either the positive or the negative sense.The root-mean-square (rms) value of an a.c. voltage or current. For a sinusoidal waveform, the rms value is 0.707 times the peak value (amplitude). A.C. voltages or currents are always quoted in rms values unless otherwise specified.The average value of an a.c. voltage or current is zero over one complete cycle so, when used, it applies only over one half cycle. Therefore, the average value for one-half cycle of a sine wave is 0.637 times the peak value. Average values are of little relevance to a.c. calculations.


If a sine wave has a peak-to-peak current value of 10 Awhat is its rms value?

The root-mean-square (rms) value of a sinusoidal voltage or current is given by: Vrms = 0.707 Vmax and Irms = 0.707 ImaxSo, if the current has a peak-to-peak value of 10 A, then Imax will be half that value (5 A) , so the corresponding rms value is:Irms = 0.707 Imax = 0.707 x 5 = 3.54 A(Answer)


Why is the class A current less than the peak current?

Not sure what you mean by Class A current. Normally, when measuring AC voltage or current you either measure the peak to peak value or the Root Mean Squared (RMS) value. Since RMS is essentially an average measured over time, it would always be less than Peak to Peak value.


What is RMS value of an AC Sinusoidal Waveform and the power they carry?

Hi, RMS is voltage X .707 and the power is voltage X current. Hope that helps, Cubby


What is RMS Peak value and average value?

RMS is used to determine the average power in an alternating current. Since the voltage in an A/C system oscillates between + and -, the actual average is zero. The RMS or "nominal" voltage is defined as the square root of the average value of the square of the current, and is about 70.7% of the peak value.************************************************************The r.m.s. value of an alternating current or voltage is the value of direct current or voltage which produces the same heating effect.Fo a sine wave, the r.m.s. value is 0.707 x the peak value.The average value is different; for a sine wave it is 0.636 x the peak value.


Convert ac voltage rms to dc voltage?

The dc voltage of a rectified ac voltage will be the peak value of the ac voltage less the forward voltage drop of the diode.The rms voltage of a sinusoidal ac voltage is sqrt(peak) / 2, but you also have to consider if the ac voltage is balanced around zero.For a normal US house voltage of 117VAC, the peak voltage is about 165V, or 330V peak to peak. Your dc voltage is then around 164V.Run that rectified voltage through a capacitor, and you will still have 164V peak value, but the voltage over time will dip because the capacitor will discharge during diode off time, and recharge when it turns back on.AnswerA given value of a.c. rms voltage is exactly equivalent to the corresponding value of d.c. voltage. For example, 120 V (rms) is exactly equivalent to 120 V d.c. This is why the alternative name for 'rms voltage' is 'effective voltage'. This is based on the fact that a current of, say, 10 A (rms) will do exactly the same amount of work as a d.c. current of 10 A. And, of course, voltage and current are proportional.


Conversion of RMS CURRENT to peak current?

In an AC circuit the voltage and current are n the form of a sine wave that goes between a maximum and minimum value 60 times a second. Measuring the difference between these values is a peak-to-peak measurement. Root Mean Square (RMS) computes an average (mean). To convert RMS to peak, multiply the RMS figure by 1.41. 1.41 is an approximation of the value of the square root of 2.