NEET-XI-Physics
exam-2 year:2016
- #134Three sound waves of equal amplitudes have
frequencies (n - 1), n, (n + 1). They superimpose
to give beats. The number of beats produced per
second will be :-
(1) 3
(2) 2
(3) 1
(4) 4digAnsr: 2Ans : (2)
Sol. n-1 n n+1
2
1 1
Now divide 1 second into 1, 1, 2 equal divisions
1
1
1
1
1
2
2
2
By eliminating common time instants, total maxima
in one second is 2.
So, two beats per second will be heard.