JEE Main & Advanced Physics Kinetic Theory of Gases Question Bank Self Evaluation Test - Kinetic Theory

  • question_answer
    One kg of a diatomic gas is at a pressure of \[8\times {{10}^{4}}N/{{m}^{2}}.\] The density of the gas is4kg/m3. What is the energy of the gas due to its thermal motion?

    A) \[5\times {{10}^{4}}J\]            

    B) \[6\times {{10}^{4}}J\]

    C) \[7\times {{10}^{4}}J\]            

    D) \[3\times {{10}^{4}}J\]

    Correct Answer: A

    Solution :

    [a] \[\text{Volume=}\frac{\text{mass}}{\text{density}}=\frac{1}{4}{{m}^{3}}\] \[\text{K}\text{.E}\text{.}=\frac{5}{2}PV=\frac{5}{2}\times 8\times {{10}^{4}}\times \frac{1}{4}=5\times {{10}^{4}}J\] Alternatively: \[\text{K}\text{.E}\text{.}=\frac{5}{2}nRT=\frac{5}{2}\frac{m}{M}RT=\frac{5}{2}\frac{m}{M}\times \frac{PM}{d}\] \[\left[ \therefore PM=dRT \right]\] \[=\frac{5}{2}\frac{mP}{d}=\frac{5}{2}\times \frac{1\times 8\times {{10}^{4}}}{4}=5\times {{10}^{4}}J\]


You need to login to perform this action.
You will be redirected in 3 sec spinner