Want this question answered?
The RMS value of an AC voltage is VRMS = VPEAK / sqrt(2), where VPEAK = the voltage peak to neutral.AnswerThe average value of a sinusoidal a.c. voltage is zero.
maximum or peak value
The term is 'alternating voltage', not 'alternate voltage'. For an a.c. voltage or current, the average value is taken over half its wavelength because, over a complete wavelength it is, of course, zero. For a sine wave, the average value (over half a wavelength) is 0.637 Vmax or 0.637 Imax.
RMS stands for root mean square. This is done so that negative values are then treated as positive values. In AC power for example, the voltage varies between a negative and a positive value. The number is squared and then the square root of this value is taken and the mean (average) of these numbers gives the answer. For example -40 is squared to become 1600 and then the square root of 1600 is taken to become 40 (a negative number becomes a positive number).If this wasn't done then the average value of AC power would be zero.
Unless otherwise stated, the value of an a.c. current or voltage is expressed in r.m.s. (root mean square) values which, for a sinusoidal waveform, is 0.707 times their peak value. The output of a voltage (or potential) transformer is no different, its measured voltage will be its r.m.s value which is lower than its peak value.
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.
EFFECTIVE HOW ABOUT AVERAGE .639 of peak.AnswerThe 'effective' value of an a.c. voltage (or current) is the same as its 'root-mean-square' (r.m.s.) voltage which, for a sinusoidal waveform, is 0.707 Umax.The 'average' value of an a.c. voltage (or current) is zero over a complete cycle, or 0.639 Umax, over half a cycle (usually applied to rectified waveforms).
You are, presumably, referring to alternating current, in which case the 'maximum' current is the peak or amplitude of the waveform. The 'average' value of current is zero, because the average value of the first half of each cycle is negated by the average value over the second half of each cycle. This is why a.c. currents and voltages are always expressed in 'root-mean-square' (r.m.s.) values which is the value of an a.c. current that does the same amount of work as a given value of d.c. current. The r.m.s. value for a sinusoidal current (and voltage, as voltage and current are proportional) is 0.707 times the peak or maximum value.
To get the average:Volts avg=0.637 X Vp (peak)0.637 X 80 Vp = 50.96 VavgTo get rms (root mean square):Volts rms = 0.707 X Vp (peak)0.707 X 80 Vp = 56.56 VrmsCommentIt should be pointed out that the average value, described above, is for half a cycle. The average for a complete cycle is zero.
rms values refer to "root mean square" mathematical values of the sine wave of electricity. This is essentially an "average" value of the voltage being measured as voltage in any circuit varies constantly.
The average value of an a.c. voltage or current, over a complete cycle, is zero. For this reason, the average value is normally quoted over a half cycle and, for a sinusoidal waveform, is equal to 0.637 Vmax or 0.637 Imax.
We will always calculate rms value only since the average value of ac current or voltage is zero. So we are using rms values in the ac circuit to calculate the power and to solve an ac circuit.
The RMS value of an AC voltage is VRMS = VPEAK / sqrt(2), where VPEAK = the voltage peak to neutral.AnswerThe average value of a sinusoidal a.c. voltage is zero.
reciprocal of the square root of 2, converts from peak voltage to rms voltageAnother AnswerThis figure results when you work out how much work is done by one complete cycle of a.c. current. Since work is proportional to the square of a current, if you divide one complete cycle of a sine wave current into lots and lots of instantaneous values, square each of these values, find their average (mean) value, then find the square root of that value, you will have found the 'root-mean-square' of the current over a complete cycle. This value always works out to 0.707 x the peak or maximum value of the sine wave. For other waveforms, other r.m.s. values result.
maximum or peak value
The term is 'alternating voltage', not 'alternate voltage'. For an a.c. voltage or current, the average value is taken over half its wavelength because, over a complete wavelength it is, of course, zero. For a sine wave, the average value (over half a wavelength) is 0.637 Vmax or 0.637 Imax.
RMS stands for root mean square. This is done so that negative values are then treated as positive values. In AC power for example, the voltage varies between a negative and a positive value. The number is squared and then the square root of this value is taken and the mean (average) of these numbers gives the answer. For example -40 is squared to become 1600 and then the square root of 1600 is taken to become 40 (a negative number becomes a positive number).If this wasn't done then the average value of AC power would be zero.