In a sine wave, what does the 180-degree mark represent?

In a sine wave, the 180-degree mark corresponds to the Peak Negative value. At this point in the cycle, the waveform has moved from its peak positive value, passed through zero volts, and is now at its lowest point, which represents the maximum negative voltage.

Understanding the sine wave's structure is crucial, as it represents how alternating current (AC) voltage varies over time. Each full cycle of a sine wave is 360 degrees. At 0 degrees, the value starts from zero and rises to its peak positive value at 90 degrees. It then returns to zero at 180 degrees, but instead of reaching a positive peak, the sine wave continues downward to the peak negative value at 270 degrees, before returning to zero again at 360 degrees.

This cyclical behavior is fundamental to the analysis of AC systems, and knowing the significance of these key points, such as where the sine wave reaches positive and negative extremes, helps in understanding phase relationships and the characteristics of AC signals.