ATI T-5 Practice Test 2025 - Free ATI T-5 Practice Questions and Study Guide

The average value of a sine wave over one complete cycle (or alternation) is zero because the positive and negative halves of the wave cancel each other out. However, when considering the average value over two alternations or two complete cycles, we analyze the structure of the sine wave more closely.

For a sine wave, the average value can be calculated by integrating the sine function over the interval of interest. In the case of two alternations, which includes both the positive and negative halves of the sine wave, the average is derived from the area above the axis (positive half) and the area below the axis (negative half). Specifically, the average value of the sine wave during the positive half is a positive quantity, while the negative half contributes equally but with a negative sign.

To arrive at the average value over two complete cycles, one typically takes the area of the positive half and divides it by the total time period. This results in an average value that represents the effective voltage of the waveform, often leading to a value expressed as a fraction of the peak voltage (Vp).

In this case, the average value of the sine wave over two alternations is calculated to be 0.636 times Vp. This value reflects the contribution of the