Question

If $C_s$ be the velocity of sound in air and C be the rms velocity, then?

• A. $C_s<C$
• B. $C_s=C$
• C. $C_s=C{\left(\frac{\gamma }{3}\right)}^{1/2}$
• D. None of these

Answer 1

The correct option is C $C_s=C{\left(\frac{\gamma }{3}\right)}^{1/2}$

$C_s=\sqrt{\frac{\gamma P}{\rho }}=\sqrt{\frac{\gamma RT}{M}}$---------- ()

C= $\sqrt{\frac{3RT}{M}}$-------(2)

From (1) and (2), we get, $C_s=C\sqrt{\frac{\gamma }{3}}$