JEE Main 2026 — Kinetic Theory of Gases Question with Solution
JEE Main 2026 (22 January Shift 1)
Question
The volume of an ideal gas increases 8 times and temperature becomes of initial temperature during a reversible change. If there is no exchange of heat in this process then identify the gas from the following options (Assuming the gases given in the options are ideal gases):
Choose an option
Show full solutionCorrect option: D
Correct answer
DHe
Step-by-step explanation
For an adiabatic process () with an ideal gas:
Given: and
Applying the adiabatic relation:
This value corresponds to a monatomic gas. Among the options, only He is monatomic ( for monatomic ideal gases). O₂ and N₂ are diatomic (), CO₂ is polyatomic (), and NH₃ is polyatomic.
Given: and
Applying the adiabatic relation:
This value corresponds to a monatomic gas. Among the options, only He is monatomic ( for monatomic ideal gases). O₂ and N₂ are diatomic (), CO₂ is polyatomic (), and NH₃ is polyatomic.
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This is a previous-year question from JEE Main 2026, covering the Kinetic Theory of Gases chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.