Two sources of sound placed close to each other, are emitting progressive waves given by
y₁ = 4sin 600π t and y₂ = 5 sin 608πt

An observer located near these two sources of sound will hear

4 beats per second with intensity ratio 25: 16 between waxing and waning

8 beats per second with intensity ratio 25:16 between waxing and waning

8 beats per second with intensity ratio 81:1 between waxing and waning

4 beats per second with intensity ratio 81:1 between waxing and waning

Solution

4 beats per second with intensity ratio 81:1 between waxing and waning

Given, y₁ = 4sin 600π t and y₂ = 5 sin 608πt
Comparing with general equation
y = a sin 2πft
we get, f₂ = 300 Hz and f₂ 304 Hz
Number of beats = f₂-f₁ = 4s^-1
$straight I subscript max over straight I subscript min space equals space open parentheses fraction numerator a subscript 1 plus a subscript 2 over denominator a subscript 1 minus a subscript 2 end fraction close parentheses squared space equals space open parentheses fraction numerator 4 plus 5 over denominator 4 minus 5 end fraction close parentheses squared space equals space 81 over 1$