The beat frequency observed when two sound waves `y_(1)=0.5sin(410t)` and `y_(2)=0.5sin(454t)` travel in the same direction is

Options

A. 5
B. 3
C. 7
D. 2

Answer

C

Explanation

We have, `y_(1)=0.5sin(410t)`
and `y_(2)=0.5sin(454t)`
From this equation given `omega_(1) and omega_(2)`
i.e., `omega_(1)=410`
`2pin_(1)=410`
`n_(1)=(410)/(2pi)=65.2`
again `omega_(2)=454`
`2pin_(2)=454`
`n_(2)=(454)/(2pi)=72.2`
The beat frequency `n=n_(1)~n_(2)`
`=72.2-65.2=7`