The root mean square speed of molecules of a gas is equal to (where, m = mass of the molecule K = Boltzman's constant, T = absolute temperature)

A. $$\sqrt {\frac{{2{\text{KT}}}}{{\text{m}}}} $$

B. $$\sqrt {\frac{{3{\text{KT}}}}{{\text{m}}}} $$

C. $$\sqrt {\frac{{6{\text{KT}}}}{{\text{m}}}} $$

D. $$\frac{{3{\text{KT}}}}{{\text{m}}}$$

Answer: Option B

Solution(By Examveda Team)

empirical relation:
Root mean square speed $$ = \sqrt {\frac{{3KT}}{m}} $$

Whereas average velocity $$ = \sqrt {\frac{{8KT}}{{\pi m}}} $$