Question

If the distribution of molecular speeds of a gas is as per the figure shown below, then the ratio of the most probable, the average, and the root mean square speeds, respectively, is

• A. $1:1:1$
• B. $1:1:1.224$
• C. $1:1.128:1.224$
• D. $1:1.128:1$

Answer 1

Answer: (B)

Due to symmetrical graph given, the average value of velocity will be at the middle, which is also most probable velocity.
While calculating rms speed, we have to take average of square of speeds and its root. In square of speeds, higher speeds will give more contribution. So the value will be more than the average value.