There are three sources of sound of equal intensity with frequencies 400, 401 and 402 vib/sec . The number of beats heard per second is

Options

A. 0
B. 1
C. 2
D. 3

Answer

C

Explanation

The no. of beats heard per second will be equal to the maximum frequency difference of the sources if frequencies of the sources vary with equal value gaps
So maximum no. of beats heard per second=402-400=2