If a source of frequency n moving with velocity v crosses a stationary observer, then the change in the frequency of sound heard by the observer will be (velocity of sound = V)

Options

A. `(2nV v)/(V^(2)+v^(2))`
B. `(2nVv)/((V^(2)-v^(2)))`
C. `(2nVv)/((V+v))`
D. `(2nVv)/((V-v))`

Answer

B

Explanation

`Deltan=n_(i)=n_(f)`
`=((V)/(V-v)-(V)/(V+v))n=(2nVv)/(V^(2)-v^(2))`