Q. A given mass of a gas is allowed to expand freely until its volume becomes double. If $C_{b}$ and $C_{a}$ are the velocities of sound in this gas before and after expansion respectively, then $C_{a}$ is equal to
A) $2C_{b}$
B) $\sqrt{2}C_{b}$
C) $C_{b}$
D) $\frac{1}{\sqrt{2}}C_{b}$
Explanation
(c) For ideal gas, on free expansion there is no change in temperature. Hence $C_{a} = C_{b}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.