TS EAMCET 9-Sep-2020 Shift 2 Solved Paper

Here a source is moving away from a stationary observer.
So, frequency recorded at source will be lower than true frequency.
Apparent frequency at observer,
f′=f(‌

v

v+vs

)
where, v= speed of sound =340m/s
and vs=72km/h=72×‌

5

18

=20ms−1
∴‌‌f′=2000(‌

340

340+20

)