The pressure of a gas is raised from 27°C to 927°C. The

The pressure of a gas is raised from 27°C to 927°C. The root mean square speed is

1. √(927/27) times the earlier value
2. remain the same
3. gets halved
4. get doubled

c_rms ∝ √T
As temperature increases from 300 K to 1200 K that is four times, so, c_rms will be doubled.