interaction

A voltage or current whose direction changes periodically over time. It passes through the zero point when the direction changes, and when averaged, the positive and negative values cancel each other out to become zero. The basic form is a sine wave, but when harmonic components are added, it becomes a distorted wave. When converting alternating current to direct current, the average value is zero, so the effective (RMS) value is used. The effective value is calculated by integrating the square of the voltage or current over one period, dividing by the period, and then taking the square root of that value.