JEE Main 2019PhysicsKinetic Theory of GasesMediumMCQ

JEE Main 2019 — Kinetic Theory of Gases Question with Solution

JEE Main 2019 (10 Jan Shift 2)

Question

2 kg of a monoatomic gas is at a pressure of 4×104 N m-2. The density of the gas is 8 kg m-3. What is the order of energy of the gas due to its thermal motion?

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Show full solutionCorrect option: C
Correct answer
C104 J

Step-by-step explanation

Internal energy is the energy due to thermal motion.

The internal energy of an ideal gas given by

U=f2nRT (for n moles)

U=f2PV=f2×P×Mρ (Since, f=3  for a monoatomic gas.)

U=32×4×104×28

=1.5×104J
So, the order of energy due to thermal motion is 104

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About this question

This is a previous-year question from JEE Main 2019, 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.