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The coercivity of a small magnet where the ferromagnet gets demagnetized is 3 × 10 3 Am –1 . The current required to be passed in a solenoid of length 10 cm and number of turns 100, so that the magnet gets demagnetized when inside the solenoid, is -

1. 60 mA
2. 3 A
3. 6 A
4. 30 mA

Correct answer: 3 A

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