RMS value of an AC voltage measuring 340 V peak-to-peak.

• A. 170
• B. 85.1
• C. 120.19
• D. 240.3

Answer: (C)

For a sinusoidal AC, the RMS value is the peak value divided by the square root of 2, and the peak value is half of the peak-to-peak value. So with a peak-to-peak of 340 V, the peak is 340/2 = 170 V. Then Vrms = 170 / √2 ≈ 170 / 1.414 ≈ 120.2 V. That aligns with about 120.19 V.

So the RMS value is around 120.2 V, not the peak (170 V), and not half of the peak or some other combination.