In an AC circuit with no phase lead or lag, which statement is true?

In an AC circuit with no phase lead or lag, the relationship between real power and apparent power can be understood through the definitions of these types of power. Real power, measured in watts, represents the actual power consumed by the load to perform useful work. Apparent power, measured in volt-amperes (VA), is the product of the voltage and current in the circuit, without considering the phase difference.

When there is no phase lead or lag, it indicates that the voltage and current are perfectly in phase. In this scenario, the real power is equal to the apparent power. This is because all the power is being effectively used and none is reactive, leading to a unity power factor.

Thus, while it may seem intuitively that the apparent power could be zero, this isn't true for a functioning AC circuit where voltage and current are present. Therefore, the correct statement reflects that in the case of no phase difference, real power equals apparent power. Hence, in this context, one should conclude that real power cannot be zero, nor can apparent power be zero, as both components are active in the circuit.