AP EAMCET Engineering 20 Apr 2019 Shift 1 Paper

The apparent frequency heard is given as
f′=(

v+v0

v−vs

)f‌‌‌......(1)
Here, the source is stationary, it means vs=0
It is given that the speed of source is equal to

1

5

times the speed of sound that is,
v0=

v

5

Therefore, from equation (1), we get
f′=(

v+ v 5

v

)f=1.2f
The wavelength remains unchanged irrespective of the motion of the observer.