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Saturday, 31 October

JEE Main 2021 · PhysicsNumerical answerNumerical valueMediumCalculation

JEE Main 31 August 2021, Shift 2, Physics Q29

Question 29 of 90 in this shift, Physics question 29 of 30, Section B.

A long solenoid with 1000 turns/m has a core material with relative permeability 500 and volume 10310^3 cm3^3. If the core material is replaced by another material having relative permeability of 750 with same volume maintaining same current of 0.75 A in the solenoid, the fractional change in the magnetic moment of the core would be approximately (x499)\left(\frac{x}{499}\right). Find the value of xx.

Official answer

250

NTA final key.

Chapter
Magnetism and Matter
Topic
Magnetic Dipole Moment
Idea tested
Magnetic Moment of a Solenoid

Same topic in other shifts

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Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.