TS EAMCET 10-Sep-2020 Shift 1 Solved Paper

According to Doppler's effect,
Observed frequency of sound reflected from building is given by
f′=f(‌

v+vb

v−vb

)....(i)
Here, v= speed of sound =340m/s
vb= speed of bus =7.2km/h=20ms−1
and f= original frequency produced by horn
=1.7kHz
Hence, putting these value in Eq. (i), we get Observed frequency by bus driver,Hence, putting these value in Eq. (i), we get Observed frequency by bus driver,