First slide

Speed of wave

Question

Velocity of sound in hydrogen gas at $27^{0} C i s V .$ Then what is the velocity of sound in helium gas at $127^{0} C ?$

Easy

A

$\frac{3 \sqrt{2}}{7} V$
B

$\frac{7 \sqrt{3}}{5} V$
C

$\frac{3 V}{4}$
D

$\frac{5 \sqrt{2} V}{3 \sqrt{7}}$

Solution

(4)
Velocity of sound $V_{S} = \sqrt{\frac{γ R T}{M}}$
$\begin{array}{l} N o w f o r H_{2}, γ = \frac{5 + 2}{5} = \frac{7}{5}, f o r H e, γ = \frac{3 + 2}{3} = \frac{5}{3} \\ ∴ \frac{V_{H e}}{V_{H_{2}}} - \sqrt{\frac{δ_{H e}}{δ_{H_{2}}}} . \sqrt{\frac{M_{H_{2}}}{M_{H e}}} . \sqrt{\frac{T_{H e}}{T_{H_{2}}}} = \sqrt{\frac{5}{3} . \frac{5}{7}} . \sqrt{\frac{400}{300}} . \sqrt{\frac{m}{2 m}} \\ \Rightarrow \frac{V_{H e}}{V_{}} = \frac{5}{\sqrt{21}} . \frac{2}{\sqrt{3}} . \frac{1}{\sqrt{2}} = \frac{5 \sqrt{2}}{5 \sqrt{7}} \Rightarrow V_{H e} = \frac{5 \sqrt{2} . V}{3 \sqrt{7}} \end{array}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App