JEE Main20209 Jan 2020Evening ShiftPhysicsKinetic Theory of GasesActual
Two gases - argon (atomic radius 0.07 n m , atomic weight 40 ) and xenon (atomic radius 0.1 n m , atomic weight 140 ) have the same number density and are at the same temperature. The ratio of their respective mean free times is closest to:
Options
- A3.67
- B1.83
- C2.3
- D4.67
Correct answer
B. 1.83
Step-by-step solution
Mean free time = 1 2 n π d 2 v r m s t A r t X e = d X e 2 d A r 2 × m 1 m 2 = 0.1 0.07 2 × 40 140 = 10 7 2 × 2 7 = 1.09 closest value is 1 . 83