The speed of sound in air at temperature $T$ and pressure $p$ is $v$. When the temperature is increased to $2 T$ and the pressure is reduced to $\frac{p}{2}$, then the speed is changed to

If at the same temperature and pressure,the densities of two diatomic gases are respectively $d_1$ and $d_2$,then the ratio of the velocities of sound in these gases will be

Match the following:

Column-$I$	Column-$II$
$(a)$ Transverse wave through a steel rod	$(i)$ $\sqrt{B + \frac{4}{3} \frac{\eta}{\rho}}$
$(b)$ Longitudinal waves in earth's crust	$(ii)$ $\sqrt{\frac{\eta}{\rho}}$
$(c)$ Longitudinal waves through a steel rod	$(iii)$ $\sqrt{\frac{2 \pi T}{g \lambda}}$
$(d)$ Ripples	$(iv)$ $\sqrt{\frac{Y}{\rho}}$

Speed of sound at constant temperature depends on

An engine approaches a hill with a constant speed. When it is at a distance of $0.9 \ km$,it blows a whistle,and the echo is heard by the driver after $5 \ s$. If the speed of sound in air is $330 \ m/s$,the speed of the engine is .... $m/s$.

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