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In three-phase systems, we always consider individualline or phase currents, or individual line or phase voltages. In other words, we treat currents and voltages no differently from single-phase currents or voltages (i.e. we don't 'combine' them because they are three-phase quantities). So these quantities are expressed in r.m.s. values.
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If a single phase 240 Volt ac is applied to a full wave bridge rectifier. what will be the resultant dc voltage?
A: the rms value will be169 volts add a capacitor and no load 240 volts and the average will be 153 volts
What is the effective value of 200 volts peak-to-peak?
200 volts peak-to-peak is 100 volts peak, which is 70.7 volts rms (standing for root-mean-square) also called "effective". This 70.7 volts is the DC voltage with the same heating power as the peak-to-peak. The relationship is: rms (aka RMS) equals peak-to-peak divided by 2, then divided again by square-root of 2 (1.414). The division by 2 gets us from peak-to-peak to just peak. The next division takes us to rms. If you get an AC voltrage with no description, for exmple 120 volts AC, it is RMS (effective). The USA AC standard supply voltage is 120 (also called 117) volts RMS. The USA peak is 117 x 1.414 (square root of 2) = 165 volts peak, = 330 volts peak-to-peak.
What is the formula for calculating DC votage from a 3 phase rectifier bridge using AC voltage across one phase?
A 3-phase rectifier bridge can be used with a single phase supply, it just means that four of the diodes are not connected. The peak voltage (if a reservoir capacitor is used) is sqrt(2) times the rms supply voltage and the average voltage using inductor smoothing is 0.9 times the rms voltage.
Rms value defination?
Because alternating current (AC) voltage varies over time, to the positive and negative, an actual AC voltage measurement will not be the same as a DC voltage measurement. For example: 5 volts DC is 5 volts constantly, viewed over time. The average voltage is 5 volts. 5 volts AC (from zero to peak) is not actually 5 volts constantly, but varies between 5 volts and 0 volts over time. The average voltage will not be 5 volts. Using RMS AC values is designed to make AC and DC measurements equivalent, for example 5 volts DC and 5 volts RMS AC are almost identical.
What is called an effective voltage in Alternating current and if you mention 115 V ac 3 phase means peak voltage is 115 or it is an effective voltage?
115 is the RMS voltage. The actual voltage is a sine wave from -167 to +167 relative to ground. RMS stands for root-mean-square, and it a way of saying that 155 Volts of DC would do the same work on the same sized load. There can be up to 3 phases, and they are the sine wave, shifted by a part of the curve. In most houses, there are 2 phases, and the voltage to ground for each is 110 to 120 V RMS. The voltage between the 2 is 230-240VRMS. 3 phase gets very complex. Each phase is 115 to ground or neutral. 3 PHASE 115V AC EACH PHASE IS 120 DEGRES PHASE SHIFTED THE EFFECTIVE VALUE IS .639 X 115 THE PEAK VALUE OF PHASE IS 1.41X RMS VALUE.
