$A$ source of sound of frequency $n$ is moving towards a stationary observer with a speed $S$. If the speed of sound in air is $V$ and the frequency heard by the observer is $n_1$,the value of $n_1/n$ is

$A$ 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 $= 352 \text{ m/s}$)

Two sources of sound $S_1$ and $S_2$ produce sound waves of same frequency $660\, Hz$. $A$ listener is moving from source $S_1$ towards $S_2$ with a constant speed $u\, m/s$ and he hears $10\, \text{beats/s}$. The velocity of sound is $330\, m/s$. Then, $u$ equals ... $m/s$.

Two sources $A$ and $B$ are sending notes of frequency $680 \ Hz$. $A$ listener moves from $A$ towards $B$ with a constant velocity $u$. If the speed of sound in air is $340 \ ms^{-1}$, what must be the value of $u$ so that he hears $10$ beats per second (in $ms^{-1}$)?

When the listener moves towards a stationary source with velocity $V_1$,the apparent frequency of the emitted note is $F_1$. When the observer moves away from the source with velocity $V_1$,the apparent frequency is $F_2$. If $V$ is the velocity of sound in air and $\frac{F_1}{F_2} = 2$,then find the ratio $\frac{V}{V_1}$.

$A$ source and an observer move away from each other with the same velocity of $10 \,ms^{-1}$ with respect to the ground. If the observer finds the frequency of sound coming from the source as $1980 \,Hz$, then the actual frequency of the source is (speed of sound in air $= 340 \,ms^{-1}$). (in $\,Hz$)