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Three perfect gases at absolute temperatures T_1, T_2 and T_3 are mixed. The masses of molecules are m_1, m_2 and m_3 and the number of molecules are…

JEE Main 2011 — Physics Thermodynamics

2011mcqmedium

Three perfect gases at absolute temperatures T1,T2T_1, T_2T1​,T2​ and T3T_3T3​ are mixed. The masses of molecules are m1m_1m1​, m2m_2m2​ and m3m_3m3​ and the number of molecules are n1,n2n_1, n_2n1​,n2​ and n3n_3n3​ respectively. Assuming no loss of energy, the final temperature of the mixture is :

Official previous-year question

Held on 30 Apr 2011 · Verified 6 Jul 2026.

Options

  1. A

    n1T1+n2T2+n3T3n1+n2+n3\frac{n_1 T_1+n_2 T_2+n_3 T_3}{n_1+n_2+n_3}n1​+n2​+n3​n1​T1​+n2​T2​+n3​T3​​

  2. B

    n1T1+n2T22+n3T32n1T1+n2T2+n3T3\frac{n_1 T_1+n_2 T_2^2+n_3 T_3^2}{n_1 T_1+n_2 T_2+n_3 T_3}n1​T1​+n2​T2​+n3​T3​n1​T1​+n2​T22​+n3​T32​​

  3. C

    n12T12+n22T22+n32T32n1T1+n2T2+n3T3\frac{n_1^2 T_1^2+n_2^2 T_2^2+n_3^2 T_3^2}{n_1 T_1+n_2 T_2+n_3 T_3}n1​T1​+n2​T2​+n3​T3​n12​T12​+n22​T22​+n32​T32​​

  4. D

    (T1+T2+T3)3\frac{\left(T_1+T_2+T_3\right)}{3}3(T1​+T2​+T3​)​

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