Characteristics of Beats #8211; (i) One rise and one fall constitutes one beat, (ii) Number of beats in one second is known as beat frequency, (iii) Time interval between two successive beats, is called beat period, (iv) If f<sub>1</sub> and f<sub>2</sub> are the frequency (f<sub>1</sub> gt; f<sub>2</sub>) of the two waves, then the beat frequency, f<sub>b</sub> = f<sub>1</sub> ~ f<sub>2</sub>.