The effective value is often abbreviated as what?

The effective value is often abbreviated as what?

• A. RMS
• B. DC
• C. AC
• D. Peak

Answer: (A)

The effective value is the RMS value. It represents the heating effect of an AC waveform and is the value you would use to compare it to a DC voltage or current with the same power delivery. RMS stands for root mean square, defined as the square root of the average of the square of the instantaneous value over a full cycle. For a sinusoidal wave, V_rms equals V_peak divided by the square root of 2 (about 0.707 times the peak). So a 100 V peak sinusoid has about 70.7 V RMS. Power calculations use this RMS value: P = V_rms^2 / R or P = I_rms^2 R. The other terms describe the type of current (DC or AC) or the maximum instantaneous value (Peak), not the heating-equivalent measure.

The effective value is the RMS value. It represents the heating effect of an AC waveform and is the value you would use to compare it to a DC voltage or current with the same power delivery. RMS stands for root mean square, defined as the square root of the average of the square of the instantaneous value over a full cycle. For a sinusoidal wave, V_rms equals V_peak divided by the square root of 2 (about 0.707 times the peak). So a 100 V peak sinusoid has about 70.7 V RMS. Power calculations use this RMS value: P = V_rms^2 / R or P = I_rms^2 R. The other terms describe the type of current (DC or AC) or the maximum instantaneous value (Peak), not the heating-equivalent measure.