Physics · Thermodynamics

JEE Main 2025 — 24 January, Evening Shift — Question 52

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason(R). Assertion (A) : In an insulated container, a gas is adiabatically shrunk to half of its initial volume. The temperature of the gas decreases.

Reason (R): Free expansion of an ideal gas is an irreversible and an adiabatic process.

In the light of the above statement, choose the correct answer from the options given below :

  1. Option A:

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

  2. Option B:

    (A) is true but (R) is false

  3. Option C:

    (A) is false but ( R ) is true

    Correct
  4. Option D:

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

Answer: C

Step-by-step solution

A) T1 V1γ−1=T2 V2γ−1\mathrm{T}_{1} \mathrm{~V}_{1}^{\gamma-1}=\mathrm{T}_{2} \mathrm{~V}_{2}^{\gamma-1}

Temp increases

R) Free expansion is assumed fast, so Adiabatic

Answer key and solution verified before publishing.

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Exam
JEE Main 2025
Subject
Physics
Chapter
Thermodynamics
Topic
Different Thermodynamic Processes
Given below are two statements. One is labelled as Assertion (A) and… | JEE Main 2025 PYQ with Solution · DhiX AI