MHT CET202618 April 2026Morning ShiftPhysicsKinetic Theory of GasesActual
The r.m.s. speed of hydrogen at S.T.P. is ' u ' m/s . If the gas is heated at constant pressure till its volume becomes three times, the final temperature of the gas and the r.m.s. speed are respectively
Options
- A1092 K , 3u m/s
- B1092 K , u 3 m/s
- C819 K , 3 ,u m/s
- D819 K , u 3 m/s
Correct answer
C. 819 K , 3 ,u m/s
Step-by-step solution
Initial temperature at S.T.P. is T₁ = 273 K . At constant pressure, volume is directly proportional to absolute temperature ( V T ). Since the volume becomes three times ( V₂ = 3V₁ ), the final temperature becomes: T₂ = 3T₁ = 3 273 = 819 K The r.m.s. speed of a gas is given by u = 3RT M , which implies u T . u₂ u₁ = T₂ T₁ = 3T₁ T₁ = 3 u₂ = 3 u Answer: 819 K , 3 ,u m/s