$A$ bus is moving with a velocity of $5 \, ms^{-1}$ towards a huge wall. The driver sounds a horn of frequency $165 \, Hz$. If the speed of sound in air is $335 \, ms^{-1}$, the number of beats heard per second by the passengers in the bus will be:

When a train approaches a stationary observer,the apparent frequency of the whistle is $n'$ and when the same train recedes away from the observer,the apparent frequency is $n''$. Then,the apparent frequency $n$ when the observer moves with the train is

$A$ car $A$ is chasing another car $B$ with a speed of $20 \, m/s$,sounding a horn of frequency $180 \, Hz$. Both cars are moving towards a stationary siren of frequency $170 \, Hz$. What is the speed of car $B$ so that it does not hear any beats (in $, m/s$)? (Speed of sound $= 340 \, m/s$)

Obtain the equation of frequency observed by an observer for a moving source and a moving observer at different velocities.

$A$ table is revolving on its axis at $5$ revolutions per second. $A$ sound source of frequency $1000 \text{ Hz}$ is fixed on the table at $70 \text{ cm}$ from the axis. The minimum frequency heard by a listener standing at a distance from the table will be .... $\text{ Hz}$ (speed of sound $= 352 \text{ m/s}$)

Doppler shift in frequency does not depend upon: