PHASE COINCIDENCE

Phase coincidence means that two waves begin at exactly the same moment. They are “lined up.” This is shown in Fig. 1 for two waves having different amplitudes. (If the amplitudes were the same, you would see only one wave.) The phase difference in this case is 0°. If two sine waves are in phase coincidence, the peak amplitude of the resulting wave, which also will be a sine wave, is equal to the sum of the peak amplitudes of the two composite waves. The phase of the resultant is the same as that of the composite waves.

Fig. 1. Two sine waves in phase coincidence.