JEE Main 2021PhysicsThermodynamicsHardMCQ

JEE Main 2021 — Thermodynamics Question with Solution

JEE Main 2021 (20 Jul Shift 1)

Question

The entropy of any system is given by, 
S=α2βlnμkRJβ2+3
where α and β are the constants. μ,J,k and R are number of moles, mechanical equivalent of heat, Boltzmann's constant and gas constant, respectively.
Take S=dQT
Choose the incorrect option from the following:

Choose an option

Show full solutionCorrect option: D
Correct answer
Dα and k have the same dimensions.

Step-by-step explanation

S=α2βℓnμkRJβ2+3
S=QT=Joule k-1
α2β=Joule k-1
PV=nRT  μkRJβ2=1

R= Joule k
⇒R= Joule k,k= Joule R
⇒β= Joule k
α2β= Joule k
⇒α= dimensionless

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About this question

This is a previous-year question from JEE Main 2021, covering the Thermodynamics 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.