In a resistive circuit, the phase relationship between voltage and current is described as:

In a resistive circuit, the current and voltage are described as being in phase. This means that the current and voltage reach their maximum and minimum values simultaneously. When the voltage waveform increases, the current waveform also increases at the same moment, and similarly for the decreases.

This in-phase relationship is fundamental to understanding resistive circuits, as it highlights that there is no phase shift between voltage and current. In other words, the energy is neither stored nor returned by reactive components such as capacitors or inductors, which would cause a phase difference. Instead, in a purely resistive circuit, the energy is used immediately in the load, and the two waveforms correlate directly. Thus, the correct characterization of how voltage and current interact in a resistive circuit is that they are in phase.