PEAK AMPLITUDE

The peak amplitude of an ac wave is the maximum extent, either positive or negative, that the instantaneous amplitude attains. In many waves, the positive and negative peak amplitudes are the same. Sometimes they differ, however. Figure 1 is an example of a wave in which the positive peak amplitude is the same as the negative peak amplitude. Figure 2 is an illustration of a wave that has different positive and negative peak amplitudes.

Fig. 1. Positive and negative peak amplitudes. In this case, they are equal.

Fig. 2. A wave in which the positive and negative peak amplitudes differ.