The speed of sound in oxygen $(O_2)$ at a certain temperature is $460 \,ms^{-1}$. The speed of sound in helium $(He)$ at the same temperature will be (assume both gases to be ideal): (in $\,ms^{-1}$)

$Assertion :$ The base of Laplace correction was that exchange of heat between the region of compression and rarefaction in air is negligible.
$Reason :$ Air is a bad conductor of heat and the velocity of sound in air is quite large.

$A$ sound wave passing through an ideal gas at $NTP$ produces a pressure change of $0.001 \ dyne/cm^2$ during adiabatic compression. The corresponding change in temperature $(\gamma = 1.5$ for the gas and atmospheric pressure is $1.013 \times 10^6 \ dyne/cm^2)$ is:

$A$ person in front of a mountain is beating a drum at the rate of $40$ per minute and hears no distinct echo. If the person moves $90 \, m$ closer to the mountain,he has to beat the drum at $60$ per minute to not hear any distinct echo. The speed of sound is .............. $ms^{-1}$.

The ratio of the velocity of sound in hydrogen $\left(\gamma=\frac{7}{5}\right)$ to that in helium $\left(\gamma=\frac{5}{3}\right)$ at the same temperature is

The pressure wave,$P = 0.01 \sin(1000t - 3x) \, N m^{-2}$,corresponds to the sound produced by a vibrating blade on a day when atmospheric temperature is $0 \, ^oC$. On some other day when temperature is $T$,the speed of sound produced by the same blade and at the same frequency is found to be $336 \, m s^{-1}$. The approximate value of $T$ is .... $^oC$