JEE Main 2014PhysicsMagnetic Properties of MatterEasyMCQ

JEE Main 2014 — Magnetic Properties of Matter Question with Solution

JEE Main 2014 (06 Apr)

Question

The coercivity of a small magnet, where the ferromagnet gets demagnetised is 3×103 A/m. The current required to be passed in a solenoid of length 10 cm and number of turns 100, so that the magnet gets demagnetised when inside the solenoid is

Choose an option

Show full solutionCorrect option: C
Correct answer
C3 A

Step-by-step explanation

For solenoid, the magnetic field needed to be magnetised the magnet.

B=μ0nI

where, n=100,l=10 cm=10100 m=0.1 m

⇒3×103=1000.1×I

⇒I=3 A

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About this question

This is a previous-year question from JEE Main 2014, 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.