To determine the average current of an alternating current (AC) waveform, we need to consider the shape of the waveform and the ratio between the on and off times.
In the case of a rectangular waveform, the current alternates between two levels: a positive value and a negative value. The average current can be calculated by taking the average of these two levels, considering the time ratio.
In this scenario, the alternating current has an amplitude of 20, which means it alternates between +20 and -20. The time period of the waveform is 1 second, given a frequency of 1 Hz.
Since the rectangular waveform spends an equal amount of time in both the positive and negative regions, the average current will be zero. This is because the positive and negative values cancel each other out over time.
Therefore, the average current in this case is 0, and none of the options you provided (20, 10, 5, or 2) is correct.