Q 11-12-022NEETJEE MainMedium
At what temperature will the rms speed of hydrogen molecules equal the rms speed of oxygen molecules at $320$ K?
Answer: (D) $20$ K
Concept. $v_{\text{rms}} \propto \sqrt{\dfrac{T}{M}}$.
Step 1. Equal speeds. $\dfrac{T_H}{2} = \dfrac{320}{32} \Rightarrow T_H = 20$ K.
Answer. $20$ K (Option D).
Solution by Sreeraj P, M.Sc Physics