A vehicle with a horn of frequency $n$ is moving with a velocity of $30\, m/s$ in a direction perpendicular to the straight line joining the observer and the vehicle. The observer perceives the sound to have a frequency $n + {n_1}$. Then (if the sound velocity in air is $300\, m/s$)
A${n_1} = 10\,n$
B${n_1} = 0$
C${n_1} = 0.1\,n$
D${n_1} = - 0.1\,n$
AIIMS 2000,AIPMT 1998, Easy
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B${n_1} = 0$
b (b) In this case Doppler’s effect is not applicable.
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