Question

The rms velocity of an ideal gas at 27°C is 0.3 ms^-1. Its rms velocity at 927°C (in ms^-1) is

(a) 3.0

(b) 2.4

(c) 0.9

(d) 0.6

Answer 1

Correct option is (d) 0.6

27°C = 300K

927°C = 1200K

We know, RMS velocity ∝ \(\sqrt T\)

So, \(\frac{v_1}{v_2} = \sqrt{\frac {T_1}{T_2}}\)

\(\frac{0.3}{v} = \sqrt{\frac {300}{1200}}\)

⇒ v = 0.6m/s