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Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Statement I: Change in internal energy of a…

JEE Main 2026 — Physics Thermodynamics

2026mcqmedium

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R

Statement I: Change in internal energy of a system containing nnn mole of ideal gas can be written as ΔU=nCv(Tf−Ti)=nRγ−1(Tf−Ti)\Delta U = n C_v (T_f - T_i) = \dfrac{nR}{\gamma - 1}(T_f - T_i)ΔU=nCv​(Tf​−Ti​)=γ−1nR​(Tf​−Ti​), where γ=CpCv\gamma = \dfrac{C_p}{C_v}γ=Cv​Cp​​, Ti=T_i =Ti​= initial temperature, Tf=T_f =Tf​= final temperature.

Statement II: Relation between degree of freedom fff and γ(=Cp/Cv)\gamma (= C_p/C_v)γ(=Cp​/Cv​) is (γ=1+2f)\left(\gamma = 1 + \dfrac{2}{f}\right)(γ=1+f2​)

Choose the correct answer from the options given below

Official previous-year question

Held on 5 Apr 2026 · Verified 6 Jul 2026.

Options

  1. A

    Both A and R are true and R is the correct explanation of A

  2. B

    Both A and R are true but R is NOT the correct explanation of A

  3. C

    A is true but R is false

  4. D

    A is false but R is true

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