NEET Solved Paper 2016 Question 25

Question: The molecules o f a given mass o f a gas have r.m.s. velocity of $ 200,m{s^{-1}} $ at $ 27{{,}^{o}}C $ and $ 1.0\times 10^{5},N{m^{-2}} $ pressure. When the temperature and pressure of the gas are respectively, $ 127{{,}^{o}}C $ and $ 0\text{.05}\times 10^{5},N{m^{-2}}, $ the r. m. s. velocity of its molecules in $ m{s^{1}} $ is :

Options:

A) $ 100\sqrt{2} $

B) $ \frac{400}{\sqrt{3}} $

C) $ \frac{100\sqrt{2}}{3} $

D) $ \frac{100}{3} $

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Answer:

Correct Answer: B

Solution:

  • $ v\propto \sqrt{T}\Rightarrow \frac{v}{200}=\sqrt{\frac{400}{300}}\Rightarrow v=\frac{200\times 2}{\sqrt{3}}m/s $
    $ \Rightarrow $ $ v=\frac{400}{\sqrt{3}},m/s $