Question
What is the benefit of making voltage measurements with a true-RMS calculating meter?
Answer Options
- A) An inverse Fourier transform can be used
- B) The signal’s RMS noise factor is also calculated
- C) The calculated RMS value can be converted directly into phasor form
- D) RMS is measured for both sinusoidal and non-sinusoidal signals
Correct Answer: D
Explanation
The RMS (Root Mean Square) value of an AC voltage is a measure of its total power content, equivalent to the DC voltage that would dissipate the same amount of power in a resistive load. Simple AC meters often measure the peak or average voltage and then apply a conversion factor, but this only works correctly for pure sine waves.
A true-RMS calculating meter electronically squares the input waveform, averages it over time, and then takes the square root, accurately performing the RMS calculation regardless of waveform shape. The benefit is that the \text{RMS} value is accurately measured for both sinusoidal and non-sinusoidal signals (such as square waves, pulse trains, or complex audio and RF envelopes), which is essential for safely measuring the power of digital and complex voice signals.
This topic was automatically created to facilitate community discussion about this exam question. Feel free to share study tips, memory tricks, or additional explanations!