Question:
When two waves of almost equal frequencies n1 and n2 reach at a point simultaneously, what is the time interval between successive maxima?
Solution:
It is given that the two frequencies are almost equal, that is n1 = n2.
For the formation of the beats, the frequencies must be n2 > n1.
The no.of frequencies per second in maxima = n = n2 – n1
Therefore, the time period of the maxima = 1/n = 1/n2 – n1 second.