The velocity of sound in air is doubled when the temperature is raised from $0^{\circ} C$ to $\alpha^{\circ} C$. The value of $\alpha$ is . . . . . . .

The depth of the sea is measured by means of an echo. If the time between the moment the sound is produced and received is $3.52 \,s$, then the depth of the sea is (The compressibility of sea water is $4.84 \times 10^{-10} \,m^2 \,N^{-1}$ and its density is $1024 \,kg \,m^{-3}$): (in $km$)

Does an oscillating source always produce sound waves?

An ultrasonic signal sent from $SONAR$ returns to it after reflection from a rock after a lapse of $1 \, s$. If the velocity of ultrasound in water is $1600 \, m/s$,the depth of the rock in water is ..... $m$.

$A$ source of sound of frequency $600 Hz$ is placed inside water. The speed of sound in water is $1500 m/s$ and in air is $300 m/s.$ The frequency of sound recorded by an observer who is standing in air is .... $Hz$

Which of the following waves cannot be polarized?