The temperature of an ideal gas is increased from $140 \mathrm{~K}$ to $560 \mathrm{~K}$. If the r.m.s.…

The temperature of an ideal gas is increased from $140 \mathrm{~K}$ to $560 \mathrm{~K}$. If the r.m.s. speed of gas molecules is $v$ at $140 \mathrm{~K}$, then at $560 \mathrm{~K}$, r.m.s. speed becomes
  1. $4 v$
  2. $\frac{v}{4}$
  3. $\frac{v}{2}$
  4. $2 v$

Solution

The r.m.s. speed $v$ is directly proportional to the square root of temperature $T$ in kelvin. $v \propto \sqrt{T}$ The new temperature is $T^{\prime}=4 \mathrm{~T}$ Hence, $v^{\prime}=2 v$

Asked in: MHT CET 2022 (11 Aug Shift 1)

Practice more Kinetic Theory of Gases questions on Aicharya