The wavelength of sound waves in hydrogen gas corresponding to the lower limit of audibility is ........ $m$ (speed of sound in hydrogen gas is about $1350 \, m/s$).

An earthquake generates both transverse $S$ and longitudinal $P$ waves in the earth with speeds $4.5 \,km/s$ and $8.0 \,km/s$, respectively. $A$ seismograph records that the first $P$-wave arrives $3.5 \,min$ earlier than the first $S$-wave. From the seismograph, the epicentre of the earthquake is located at a distance of: (in $\,km$)

What is called compression or condensation? Which type of changes in density and pressure take place in it?

Obtain the equation for the speed of a sound wave in air and identify the error in this equation.

What is 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? (Molecular weight of hydrogen and helium is $2$ and $4$ respectively)

$Assertion :$ 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.