JEE Main 2021PhysicsMagnetic Properties of MatterEasyNumerical

JEE Main 2021 — Magnetic Properties of Matter Question with Solution

JEE Main 2021 (27 Jul Shift 1)

Question

In a uniform magnetic field, the magnetic needle has a magnetic moment 9.85×10-2 A m-2 and moment of inertia 5×10-6 kg m2. If it performs 10 complete oscillations in 5 seconds then the magnitude of the magnetic field is ____mT  [Take π2 as 9.85

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Show full solutionCorrect answer: 8
Correct answer
8

Step-by-step explanation

T=2πIMB
B=80×10-4=8 mT

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About this question

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