JEE Main 2021PhysicsMagnetic Effects of CurrentHardNumerical

JEE Main 2021 — Magnetic Effects of Current Question with Solution

JEE Main 2021 (01 Sep Shift 2)

Question

The temperature of 3.00 mol of an ideal diatomic gas is increased by 40.0°C without changing the pressure of the gas. The molecules in the gas rotate but do not oscillate. If the ratio of change in internal energy of the gas to the amount of workdone by the gas is x10. Then the value of x (round off to the nearest integer) is _________.

( GivenR=8.31 J mol-1 K-1

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Show full solutionCorrect answer: 25
Correct answer
25

Step-by-step explanation

First, recall the formula of change in internal energy in terms of molar specific heat at constant volume and change in temperature, ∆U=nCVΔT, for diatomic gas, CV=f2R=52R, ⇒∆U=n×52×RΔT

⇒ΔUW=52nRΔTnRΔT=52=2510

So, x=25

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About this question

This is a previous-year question from JEE Main 2021, covering the Magnetic Effects of Current 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.