What happens to current and voltage in a purely resistive circuit?

In a purely resistive circuit, current and voltage are in phase, meaning that the peaks and troughs of the waveforms of both quantities occur at the same time. This relationship occurs because the resistive elements follow Ohm's Law, which states that the current through a resistor is directly proportional to the voltage across it, provided the resistance remains constant.

In practical terms, when the voltage reaches its maximum value, the current also reaches its maximum value at that same instant. Similarly, when the voltage passes through zero or reaches its minimum, the current does so at the same point in time. This synchronous behavior is critical in ensuring that energy is delivered efficiently without any phase losses that can occur in inductive or capacitive circuits.

Understanding this relationship is crucial in electrical engineering and circuit analysis, as it helps in predicting how circuits will behave under different load conditions and in designing systems that need coordinated timing between voltage and current for optimal performance.