Which statement is true about the relationship between rms voltage and DC voltage in an AC circuit?

In an AC circuit, the root mean square (rms) voltage is a specific measure of the effective value of an alternating voltage. It is defined as the DC equivalent voltage that would deliver the same average power to a load. Therefore, when comparing rms voltage to DC voltage, it is accurate to state that rms voltage can be equivalent to the DC voltage in terms of the power they can deliver to a resistive load. This allows for practical simplified calculations when dealing with alternating currents, as it translates the varying AC values into a single effective value.

The other statements do not hold true in the context of this relationship. Rms voltage is not always higher than DC voltage; it can be lower or equal depending on the waveform. Rms voltage can indeed be compared to DC voltage because they can be expressed in similar units and relate to power delivery. Finally, while it is true that rms voltage is lower than the peak voltage for sinusoidal AC signals, this does not address the relationship between rms voltage and DC voltage directly. Hence, the assertion that rms voltage is equivalent to DC voltage captures the core relationship in a straightforward manner.