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For a diatomic gas, if γ_1= ( C p C v ) for rigid molecules and γ_2= ( C p C v ) for another diatomic molecules, but also having vibrational modes.…

JEE Main 2025 — Physics Thermodynamics

2025mcqmedium

For a diatomic gas, if γ1=(CpCv)\gamma_1=\left(\frac{C p}{C v}\right)γ1​=(CvCp​) for rigid molecules and γ2=(CpCv)\gamma_2=\left(\frac{C p}{C v}\right)γ2​=(CvCp​) for another diatomic molecules, but also having vibrational modes. Then, which one of the following options is correct ? (Cp and Cv are specific heats of the gas at constant pressure and volume)

Official previous-year question

Held on 22 Jan 2025 · Verified 6 Jul 2026.

Options

  1. A

    γ2=γ1\gamma_2=\gamma_1γ2​=γ1​

  2. B

    2γ2=γ12 \gamma_2=\gamma_12γ2​=γ1​

  3. C

    γ2<γ1\gamma_2 \lt \gamma_1γ2​<γ1​

  4. D

    γ2>γ1\gamma_2\gt\gamma_1γ2​>γ1​

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