A source producing sound of frequency 170 Hz is approaching a stationary observer with a velocity `17 ms^(-1)`. The apparnet change in the wavelength of sound heard by the observer is (speed of sound in air `=340 ms^(-1))`

Options

A. `0.2 m`
B. `0.1 m`
C. `0.5 m`
D. `0.4 m`

Answer

B

Explanation

`lambda=(v)/(n)=(340)/(170)=2m`
`n'=(340)/(340-17)xx170`
`n=178.9 Hz`
Now, `lambda'= (v)/(n)=(340)/(178.9)=1.9`
`rArr lambda- lambda'=2-1.9=0.1 m`