# NEET Physics Kinetic Theory of Gases Questions Solved

A given mass of a gas is allowed to expand freely until its volume becomes double. If ${\mathrm{C}}_{\mathrm{b}}$ and ${\mathrm{C}}_{\mathrm{a}}$ are the velocities of sound in this gas before and after expansion respectively, then ${\mathrm{C}}_{\mathrm{a}}$ is equal to

1. $2{\mathrm{C}}_{\mathrm{b}}$

2. $\sqrt{2}{\mathrm{C}}_{\mathrm{b}}$

3. ${\mathrm{C}}_{\mathrm{b}}$

4. $\frac{1}{\sqrt{2}}{\mathrm{C}}_{\mathrm{b}}$

3. For ideal gas, on free expansion there is no change in temperature. Hence ${\mathrm{C}}_{\mathrm{a}}={\mathrm{C}}_{\mathrm{b}}$

Difficulty Level:

• 8%
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