Two standing bodies producing progressive waves are given by
` y_(1) = 4 sin 400 pi t and y_(2) = 3 sin 404 pi t`
One of these bodies situated very near to the ears of a person who will hear :

Options

A. 2 beats persecond with intensity ratio `(4)/(3)` between maxima andminima
B. 2 beats per second with intensity ratio 49 betweenmaxima and minima
C. 4 beats per second with intensity ratio 7 between maxima and minima
D. 4 beats per second with intensity ratio `(4)/(3)` between maxima andminima

Answer

B

Explanation

When the two waves superpose then the maximum amplitude will be 4+ 3= 7 and minimum will be 4- 3= 1 hence the ratio ofmaximum to minimum intensity will be 49 and as the frequencies of the two waves are 200Hz and 202Hz the beat frequency-will be 2Hz.