Question

The r.m.s. speed of a certain gas is ν at 400K. The temperature at which the r.m.s. speed becomes two times, will be

• A. 800 K
• B. 1600 K
• C. 1200 K
• D. None of these

Answer 1

Answer: (B)

1600 K

Answer 2

$v_{rms} \propto \sqrt{T}$Ž $\frac{T_{2}}{T_{1}} = \frac{v_{2}^{2}}{v_{1}^{2}} = \frac{4v^{2}}{v^{2}} = 4$

Ž $T_{2} = 4T_{1} = 4 \times 400 = 1600K$