The temperature of an ideal gas is increased from `140 K` to `560 K`. If a `140 K` the root mean square velocity of the gas molecule is `V`, at `560 K` it becomes

Options

A. 5 u
B. 2 u
C. u/2
D. u/4

Answer

B

Explanation

The ratio of `V_(rms)` of gas at two different temperatures is given by
`((u_(rms))_(2))/((u_(rms))_(1)) = sqrt((T_(2))/(T_(1))) , (u_(rms))_(2) = sqrt((560)/(140)) xx u = 2u`
`therefore (u_(rms))_(1) = u`