$A$ siren emitting sound of frequency $800 \; Hz$ is going away from a static listener with a speed of $30 \; m/s$. The frequency of the sound heard by the listener is... $Hz$ (take velocity of sound as $330 \; m/s$).

$A$ person with a vibrating tuning fork of frequency $338 \,Hz$ is moving towards a vertical wall with a speed of $2 \,ms^{-1}$. The velocity of sound in air is $340 \,ms^{-1}$. The number of beats heard by that person per second is

An observer and a source emitting sound of frequency $120 \,Hz$ are on the $X$-axis. The observer is stationary while the source of sound is in motion given by the equation $x=3 \sin \omega t$ (where $x$ is in metres and $t$ is in seconds). If the difference between the maximum and minimum frequencies of the sound observed by the observer is $22 \,Hz$,then the value of $\omega$ is (speed of sound in air $=330 \,ms^{-1}$):

An observer moves towards a stationary source of sound with a velocity equal to one-fifth of the velocity of sound. The percentage change in the frequency will be $\dots \;$%.

$A$ source and an observer are moving towards each other with a speed equal to $\frac{v}{2}$,where $v$ is the speed of sound. The source is emitting sound of frequency $n$. The frequency heard by the observer will be

$A$ siren emitting a sound of frequency $800 \, Hz$ moves away from an observer towards a cliff at a speed of $15 \, m s^{-1}$. The frequency of sound that the observer hears in the echo reflected from the cliff is .... $Hz$ (Take velocity of sound in air $= 330 \, m s^{-1}$)